Trajectory assistance for autonomous vehicles

ABSTRACT

An autonomous vehicle may include a stuck condition detection component and a communications component. The stuck-detection component may be configured to detect a condition in which the autonomous vehicle is impeded from navigating according to a first trajectory. The communications component may send an assistance signal to an assistance center and receive a response to the assistance signal. The assistance signal may include sensor information from the autonomous vehicle. The assistance center may include a communications component and a trajectory specification component. The communications component may receive the assistance signal and send a corresponding response. The trajectory specification component may specify a second trajectory for the autonomous vehicle and generate the corresponding response that includes a representation of the second trajectory. The second trajectory may be based on the first trajectory and may ignore an object that obstructs the first trajectory.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. patent application Ser. No.15/372,071, filed Dec. 7, 2016, which is hereby incorporated byreference in its entirety. U.S. patent application Ser. No. 15/372,071claims priority to U.S. Pat. No. 9,541,410, issued Jan. 10, 2017, whichis hereby incorporated by reference in its entirety. U.S. Pat. No.9,541,410 claims priority to U.S. Pat. No. 9,008,890, issued Apr. 14,2015, which is hereby incorporated by reference in its entirety.

BACKGROUND

Some vehicles are configured to operate in an autonomous mode in whichthe vehicle navigates through an environment with little or no inputfrom a driver. Such an autonomous vehicle (or AV) typically includes oneor more sensors that are configured to sense information about theenvironment. The autonomous vehicle may use the sensed information tonavigate through the environment. For example, if the sensors determinethat the autonomous vehicle is approaching an obstacle, the vehicle maybe able to navigate around the obstacle. An autonomous vehicle mayoperate in various weather and lighting conditions, such as, but notlimited to, days, nights, good visibility conditions, and/or reducedvisibility conditions.

SUMMARY

In one aspect, a system is provided. The system may include anautonomous vehicle and an assistance center. The autonomous vehicle mayinclude a stuck condition detection component and a communicationscomponent. The stuck condition detection component may be configured todetect a condition in which the autonomous vehicle is impeded fromnavigating according to a first trajectory. The communications componentmay be configured at least to send an assistance signal indicating thatthe autonomous vehicle seeks assistance navigating according to thefirst trajectory, and to receive a response to the assistance signal.The assistance signal may include sensor information of the autonomousvehicle, indicating low-level sensor strike input and high-level,polygonal or polyhedral representations of objects in the vicinity ofthe autonomous vehicle. The assistance center may include acommunications component and a trajectory specification component. Thecommunications component may be configured at least to receive theassistance signal, and to send the response to the assistance signal.The trajectory specification component may be configured to specify asecond trajectory for the autonomous vehicle and to generate theresponse to the assistance signal including a representation of thesecond trajectory. The second trajectory may be based on the firsttrajectory. The second trajectory may ignore the presence of at leastpart of one high-level, polygonal or polyhedral representation of anobject that obstructs the first trajectory.

In another aspect, a method is provided. An autonomous vehicle maydetect a condition in which the autonomous vehicle is impeded fromnavigating according to a first trajectory. The autonomous vehicle maysend, to an assistance center, an assistance signal that the autonomousvehicle seeks assistance navigating according to the first trajectory.The assistance signal may include sensor information of the autonomousvehicle indicating low-level sensor strike input and high-level,polygonal or polyhedral representations of objects in the vicinity ofthe autonomous vehicle. The autonomous vehicle may receive a response tothe assistance signal. The response may include a representation of asecond trajectory, where the second trajectory is based on the firsttrajectory. The second trajectory may ignore the presence of at leastpart of one high-level, polygonal or polyhedral representation of anobject that obstructs the first trajectory.

In another aspect, an autonomous vehicle is provided. The autonomousvehicle may include one or more processors and a non-transitory computerreadable medium storing instructions that, when executed by the one ormore processors, cause the autonomous vehicle to perform functions. Thefunctions may include detecting a condition in which the autonomousvehicle is impeded from navigating according to a first trajectory. Thefunctions may also include sending an assistance signal, from theautonomous vehicle to an assistance center, that the autonomous vehicleseeks assistance navigating according to the first trajectory. Theassistance signal may include sensor information of the autonomousvehicle indicating low-level sensor strike input and high-level,polygonal or polyhedral representations of objects in the vicinity ofthe autonomous vehicle. The functions may also include receiving aresponse to the assistance signal. The response may include arepresentation of a second trajectory that could be based on the firsttrajectory. The second trajectory may ignore the presence of at leastpart of one high-level, polygonal or polyhedral representation of anobject that obstructs the first trajectory.

In another aspect, a device is provided. The device may include meansfor detecting a condition in which navigation according to a firsttrajectory is impeded, and means for sending an assistance signal to anassistance center seeking assistance to navigate according to the firsttrajectory. The assistance signal may include sensor informationindicating low-level sensor strike input and high-level, polygonal orpolyhedral representations of objects in the vicinity of the device. Thedevice may also include means for receiving a response to the assistancesignal from the assistance center. The response may include arepresentation of a second trajectory, where the second trajectory maybe based on the first trajectory, and where the second trajectory mayignore the presence of at least part of one high-level, polygonal orpolyhedral representation of an object that obstructs the firsttrajectory.

In another aspect, a method is provided. It may be determined that aspeed of an autonomous vehicle is less than or equal to a thresholdspeed, and that the autonomous vehicle has not detected a trafficcontrol signal. A cause C may be identified for the speed to be lessthan or equal to the threshold speed. A timer T may be started, wherethe timer T may be based on the cause C. After the timer T expires, itmay be determined whether the cause C remains for the speed to be lessthan or equal to the threshold speed. After determining that the cause Cremains for the speed to be less than or equal to the threshold speed,an assistance signal may be sent by the autonomous vehicle indicatingthat the autonomous vehicle is stuck.

In another aspect, an autonomous vehicle is provided. The autonomousvehicle may include one or more processors and data storage storingprogram instructions that, when executed by the one or more processors,cause the autonomous vehicle to perform functions. The functions mayinclude determining that a speed is less than or equal to a thresholdspeed and that a traffic control signal has not been detected. Thefunctions may also include identifying a cause C for the speed to beless than or equal to the threshold speed, and starting a timer T. Thefunctions may further include, after the timer T expires, determiningwhether the cause C remains for the speed to be less than or equal tothe threshold speed, and, after determining that the cause C remains forthe speed to be less than or equal to the threshold speed, sending anassistance signal indicating that that the autonomous vehicle is stuck.The timer T may be based on the cause C.

In another aspect, a non-transitory computer readable medium isprovided. The non-transitory computer readable medium may storeinstructions thereon that, when executed by one or more processors,cause the one or more processors to perform functions. The functions mayinclude determining that a speed is less than or equal to a thresholdspeed, and that a traffic control signal has not been detected. Thefunctions may also include identifying a cause C for the speed to beless than or equal to the threshold speed, and starting a timer T. Thefunctions may further include, after the timer T expires, determiningwhether the cause C remains for the speed to be less than or equal tothe threshold speed, and, after determining that the cause C remains forthe speed to be less than or equal to the threshold speed, sending anassistance signal indicating that an autonomous vehicle is stuck. Thetimer T may be based on the cause C.

In another aspect, a device is provided. The device may include meansfor determining that a speed is less than or equal to a threshold speedand that a traffic control signal has not been detected. The device mayalso include means for identifying a cause C for the speed to be lessthan or equal to the threshold speed, and means for starting a timer T.The device may further include means for, after the timer T expires,determining whether the cause C remains as a cause for the speed to beless than or equal to the threshold speed, and means for, afterdetermining that the cause C remains the cause for the speed to be lessthan or equal to the threshold speed, sending an assistance signalindicating that the device is stuck. The timer T may be based on thecause C.

In another aspect, a method is provided. An autonomous vehicle maydetermine to seek assistance to navigate in accordance with a firsttrajectory. The autonomous vehicle may be configured to receive andstore data about a plurality of obstacles. A particular obstacle in theplurality of obstacles may partially or wholly obstruct the firsttrajectory. The autonomous vehicle may select a portion of the storeddata, where the portion of the stored data is less than the totality ofthe stored data and includes data representing the particular obstacle.The portion of the stored data may be provided to an assistance center.A second trajectory may be received from the assistance center, wherethe second trajectory is not obstructed by the particular obstacle.

In another aspect, an autonomous vehicle is provided. The autonomousvehicle include one or more processors and data storage storing programinstructions thereon that, when executed by the one or more processors,cause the autonomous vehicle to perform functions. The functions mayinclude determining to seek assistance to navigate in accordance with afirst trajectory. The data storage may be configured to receive andstore data about a plurality of obstacles, and a particular obstacle inthe plurality of obstacles may partially or wholly obstruct the firsttrajectory. The functions may also include selecting a portion of thestored data. The selected portion of the stored data may be less thanthe totality of the stored data and may include data representing theparticular obstacle. The functions may further include providing, to anassistance center, the portion of the stored data, and receiving, fromthe assistance center, a second trajectory. The second trajectory mightnot be obstructed by the particular obstacle.

In another aspect, a non-transitory computer readable medium isprovided. The non-transitory computer readable medium may storeinstructions thereon that, when executed by one or more processors,cause the one or more processors to perform functions. The functions mayinclude determining to seek assistance to navigate an autonomous vehiclein accordance with a first trajectory. The autonomous vehicle may beconfigured to receive and store data about a plurality of obstacles, anda particular obstacle in the plurality of obstacles may partially orwholly obstruct the first trajectory. The functions may includeselecting a portion of the stored data. The selected portion of thestored data may be less than the totality of the stored data and mayinclude data representing the particular obstacle. The functions mayfurther include providing, to an assistance center, the portion of thestored data, and receiving, from the assistance center, a secondtrajectory. The second trajectory might not be obstructed by theparticular obstacle.

In another aspect, a device is provided. The device may include meansfor determining to seek assistance to navigate an autonomous vehicle inaccordance with a first trajectory. The autonomous vehicle may beconfigured to receive and store data about a plurality of obstacles, anda particular obstacle in the plurality of obstacles may partially orwholly obstruct the first trajectory. The device may also include meansfor selecting a portion of the stored data. The selected portion of thestored data may be less than the totality of the stored data and mayinclude data representing the particular obstacle. The device mayfurther include means for providing, to an assistance center, theportion of the stored data, and means for receiving, from the assistancecenter, a second trajectory. The second trajectory might not beobstructed by the particular obstacle.

In another aspect, a method is provided. An assistance center mayreceive a representation of a first trajectory of an autonomous vehiclethat is in a stuck condition, where the first trajectory does notrelieve the stuck condition. The assistance center may receive sensorinformation of the autonomous vehicle, where the sensor information mayinclude low-level sensor strike input and high-level, polygonal orpolyhedral representations of objects in the vicinity of the autonomousvehicle. The high-level, polygonal or polyhedral representations ofobjects may be based, at least in part, on the low-level sensor strikeinput. Based on the first trajectory and the sensor information, theassistance center may determine a second trajectory that relieves thestuck condition while adhering to at least some navigationalconstraints. Relieving the stuck condition may include ignoring at leastone high-level, polygonal or polyhedral representation of an object thatobstructs the first trajectory. The assistance center may transmit arepresentation of the second trajectory and instructions for theautonomous vehicle to drive in accordance with the second trajectory.

In another aspect, a non-transitory computer readable medium isprovided. The non-transitory computer readable medium may storeinstructions thereon that, when executed by a computing device, causethe computing device to perform functions. The functions may includereceiving a representation of a first trajectory of an autonomousvehicle that is in a stuck condition. The first trajectory might notrelieve the stuck condition. The functions may also include receivingsensor information of the autonomous vehicle, where the sensorinformation may include low-level sensor strike input and high-level,polygonal or polyhedral representations of objects in the vicinity ofthe autonomous vehicle. The high-level, polygonal or polyhedralrepresentations of objects may be based, at least in part, on thelow-level sensor strike input. The functions may further include, basedon the first trajectory and the sensor information, determining a secondtrajectory that may relieve the stuck condition while adhering to atleast some navigational constraints. Relieving the stuck condition mayinclude ignoring at least one high-level, polygonal or polyhedralrepresentation of an object that obstructs the first trajectory. Thefunctions may additionally include transmitting a representation of thesecond trajectory and instructions for the autonomous vehicle to drivein accordance with the second trajectory.

In another aspect, a device is provided. The device may include meansfor receiving a representation of a first trajectory of an autonomousvehicle that is in a stuck condition. The first trajectory might notrelieve the stuck condition. The device may also include means forreceiving sensor information of the autonomous vehicle, where the sensorinformation may include low-level sensor strike input and high-level,polygonal or polyhedral representations of objects in the vicinity ofthe autonomous vehicle. The high-level, polygonal or polyhedralrepresentations of objects may be based, at least in part, on thelow-level sensor strike input. The device may also include means fordetermining a second trajectory, based on the first trajectory and thesensor information, which relieves the stuck condition while adhering toat least some navigational constraints. Relieving the stuck conditionmay include ignoring at least one high-level, polygonal or polyhedralrepresentation of an object that obstructs the first trajectory. Thedevice may additionally include means for transmitting a representationof the second trajectory and instructions for the autonomous vehicle todrive in accordance with the second trajectory.

The foregoing summary is illustrative only and is not intended to be inany way limiting. In addition to the illustrative aspects, appearances,embodiments, and features described above, further aspects, appearances,embodiments, and features will become apparent by reference to thefigures and the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart of an example method, according to an exampleembodiment.

FIG. 2 is a flow chart of another example method, according to anexample embodiment.

FIG. 3 is a flow chart of yet another example method, according to anexample embodiment.

FIG. 4 is a flow chart of still another example method, according to anexample embodiment.

FIG. 5 shows an example autonomous vehicle operating environment,according to an example embodiment.

FIG. 6 shows a scenario where an autonomous vehicle is in a stuckcondition, according to an example embodiment.

FIG. 7 is a flow chart of an example method for detecting whether anautonomous vehicle is in a stuck condition, according to an exampleembodiment.

FIG. 8 shows an example scenario where an autonomous vehicle isattempting to follow an original trajectory to destination, according toan example embodiment

FIG. 9 shows another example scenario where an autonomous vehicle isattempting to follow an original trajectory to destination, according toan example embodiment.

FIG. 10 is a flow chart of an example method where an autonomous vehiclerequests assistance from an assistance center to relieve a stuckcondition, according to an example embodiment.

FIG. 11 schematically illustrates a LIDAR unit scanning across anobstacle-filled environmental scene, according to an example embodiment.

FIG. 12 schematically illustrates an example point cloud correspondingto the obstacle-filled environmental scene of FIG. 11.

FIG. 13 schematically illustrates spatial point data indicative of asurface of a target vehicle that is stationary relative to a LIDAR unit,according to an example embodiment.

FIG. 14 schematically illustrates spatial point data indicative of asurface of a target vehicle that is moving relative to a LIDAR unit,according to an example embodiment.

FIGS. 15A, 15B, and 15C show a scenario for using a trajectory interfaceto relieve a stuck condition of an autonomous vehicle, according toexample embodiments.

FIG. 16 is a functional block diagram illustrating an autonomousvehicle, according to an example embodiment.

FIG. 17 is a functional block diagram illustrating an assistance center,according to an example embodiment.

FIG. 18 shows a vehicle that may be similar or identical to the vehicledescribed with respect to FIG. 16, according to an example embodiment.

FIG. 19A is a block diagram of a computing device, according to anexample embodiment.

FIG. 19B depicts a network of computing clusters arranged as a serversystem, according to an example embodiment.

DETAILED DESCRIPTION

Autonomous vehicles may navigate by using a number of sensors to collectinformation about objects in the vicinity of the autonomous vehicle, andby determining trajectories for the autonomous vehicle based on thiscollected information. For instance, an autonomous vehicle may beequipped with one or more video cameras, still cameras, radar units,Light Detection and Ranging (LIDAR) units, Global Positioning System(GPS) units, and/or perhaps other types of location-determining orobject-detection technologies.

For instance, the autonomous vehicle may be configured with a LIDAR unitto generate the low-level data about nearby environmental features. TheLIDAR unit may estimate distances to these environmental features whilescanning through the surroundings of the autonomous vehicle. Thus, theLIDAR unit may assemble a cloud of point positions indicative of thethree-dimensional shapes of objects in the surroundings. Individualpoints may be measured by generating a laser pulse and detecting areturning pulse, if any, reflected from an environmental object, anddetermining the distance to the reflective object according to the timedelay between the emitted pulse and the reception of the reflectedpulse.

The laser, or set of lasers, may be rapidly and repeatedly scannedacross the surroundings to provide continuous, or nearly continuous,real-time information on distances to the objects therein. Combining themeasured distances, and the orientation of the laser(s) while measuringeach distance, allows for associating a three-dimensional position witheach returning pulse. In this way, a three-dimensional map of points ofreflective features can be generated based on the returning pulses forthe entire scanning zone. Using the three-dimensional point map,high-level data defining the relative sizes, shapes, velocities, andtrajectories of various objects (such as other vehicles, pedestrians,trees, structures, etc.) can be inferred. These objects may berepresented as polygons or polyhedrons, or by other two-dimensional orthree-dimensional representations.

From this information, as well as possible navigational requests fromone or more users or controllers of the autonomous vehicle, theautonomous vehicle may develop a trajectory that it can drive from astarting point (e.g., the autonomous vehicle's current location) to anendpoint (e.g., a destination). The trajectory may also specify somenumber of intermediate waypoints through which the autonomous vehicleshould pass while navigating from the starting point to the endpoint.

While driving in accordance with such a trajectory, the autonomousvehicle may adhere to navigational constraints. For instance, theautonomous vehicle may take steps to avoid collisions, to avoid breakingtraffic laws (e.g., staying in the proper lane, obeying the speed limit,and stopping fully at stop signs), and to avoid causing inertialdiscomfort to passengers (e.g., rapid acceleration or deceleration,sudden turns, and so on) unless absolutely necessary. The autonomousvehicle may make use of low-level and high-level sensor information inorder to adhere to these constraints. Thus, for example, if theautonomous vehicle detects an obstacle in its trajectory, it may makemodifications to the trajectory in order to avoid the obstacle.

In some scenarios, an autonomous vehicle may enter into a “stuck”condition. The stuck condition may be, for instance, a condition wherethe autonomous vehicle might not be able to navigate in accordance withan original trajectory without relaxing any of its navigationalconstraints. For example, an autonomous vehicle may be configured withconstraint(s) to “stay on the road” and “do not back up while on theroad.” Then, while driving, the autonomous vehicle may determine thatthe road ahead is completely obstructed by a large object. Even if ashoulder of the road and/or the road behind the autonomous vehicle isclear, the autonomous vehicle may not be able to navigate around or awayfrom the large object. Thus, the autonomous vehicle may determine thatit is in a stuck condition.

Detecting when the autonomous vehicle is stuck may be a complex problem.Some approaches may generate an excessive number of false positiveresults. This may lead to over-allocation of resources to assist stuckautonomous vehicles. Other approaches lead to excessive amount ofwaiting until the autonomous vehicle determines that it is in a stuckcondition.

As an example, consider a heuristic of setting a timer whenever theautonomous vehicle stops, and alerting when the stoppage lasts longerthan a threshold N seconds. If the threshold N is set to 5 seconds,alerts may be sent while waiting for stop lights, when the autonomousvehicle is in stop and go freeway traffic, and when the autonomousvehicle is navigating stop signs at busy intersections. These alerts arelikely to be considered false positives. On the other hand, if N is setto 600 seconds (10 minutes), the autonomous vehicle may wait behind adouble parked car on an otherwise empty street for at least 10 minutes.In this situation, the waiting may result in a poor user experience.

Upon determining that the autonomous vehicle is in a stuck condition,the autonomous vehicle may send an assistance request to an assistancecenter to request assistance. This assistance request may include thelocation of the autonomous vehicle, as well as some basic data from oneor more of the autonomous vehicle's sensors. In response, the assistancecenter may either accept or reject the assistance request. If therequest is accepted, the assistance center may send a new trajectory foruse by the autonomous vehicle.

In some cases, in order to provide the navigational assistance, theassistance center may determine that it would benefit from additionaldata from the autonomous vehicle. The additional data may include datathat is too expensive or burdensome for the autonomous vehicle totransmit to the assistance center by default. Low-level data, such asclusters of laser strikes on surfaces in the vicinity of the autonomousvehicle, may be useful to the assistance center. For example, the laserstrike data is generally more accurate than high-level object data thatmay be, at least partially, inferred from the laser strike data.

The low-level data may be useful to an expert in the assistance center,such as a human expert and/or an expert system. However, the autonomousvehicle may generate a large enough volume of low-level data to beimpractical for the autonomous vehicle to regularly transmit. Instead,the autonomous vehicle may use heuristics to reduce the extent oftransmitted data, such as but not limited to restricting the number ofobstacles or objects to report based on proximity to the autonomousvehicle, sorting objects based on the autonomous vehicle's trajectory orlocation or perceived importance of the objects, and/or preferringexpert-friendly types of data for transmission. Additionally, oralternatively, the autonomous vehicle may restrict the data tohigh-level (e.g., polygonal or polyhedral) representations of theseobjects that were derived from the low-level data.

Being able to determine when an autonomous vehicle is stuck and thenwhen to request assistance may significantly reduce the extent ofexperts used to operate a fleet of autonomous vehicles. Such an expert,for instance as a human or an expert system, may be at an assistancecenter waiting for assistance requests. As such, one expert at anassistance center may assist multiple autonomous vehicles. Thus, ifstuck conditions can be efficiently and effectively detected, expertsmay be freed up for other tasks and the operating costs of autonomousvehicles may be reduced.

Turning to the figures, FIG. 1 is a flow chart of method 100, accordingto an example embodiment. Method 100 may be carried out by an autonomousvehicle, such as described below in the context of at least FIGS. 16 and18.

At block 110, an autonomous vehicle may detect a condition in which theautonomous vehicle is impeded from navigating according to a firsttrajectory, such as discussed below in the context of at least FIGS. 6and 7.

At block 120, the autonomous vehicle may send an assistance signal to anassistance center, such as discussed below in the context of at leastFIGS. 8-10 and 15A-15C. The assistance signal may indicate that theautonomous vehicle seeks assistance navigating according to the firsttrajectory. The assistance signal may include sensor information of theautonomous vehicle. The sensor information may indicate low-level sensorstrike input, such as laser strike input discussed below in the contextof FIGS. 11-14, and/or high-level, polygonal or polyhedralrepresentations of objects in the vicinity of the autonomous vehicle,such as discussed previously, as well as below in the context of FIGS.11-15C.

At block 130, the autonomous vehicle may receive a response to theassistance signal, such as discussed below in the context of at leastFIGS. 8-10 and 15A-15C. The response may include a representation of asecond trajectory, where the second trajectory may be based on the firsttrajectory. The second trajectory may ignore the presence of at leastpart of one high-level, polygonal or polyhedral representation of anobject that obstructs the first trajectory, such as discussed below atleast in the context of FIGS. 5, 8-10, 15A-15C, and 17. For example, anexpert at the assistance center may have determined that the object doesnot fully obstruct the first trajectory, and therefore may be at leastpartially ignored.

In some embodiments, the second trajectory may include a path defined bya plurality of points. The path defined by the plurality of points mayinclude a spline connecting at least two points in the plurality ofpoints.

Method 100 may include determining the second trajectory using an expertentity at the assistance center. The second trajectory may be determinedbased on the assistance signal and the sensor information. In someembodiments, the expert entity may include a human expert. In otherembodiments, the expert entity may include a computing system.

In further embodiments, method 100 may include the autonomous vehicleobtaining the second trajectory from the response, and driving accordingto the second trajectory. Driving the autonomous vehicle according tothe second trajectory may include driving according to the firsttrajectory after driving according to the second trajectory. Forinstance, the second trajectory may avoid one or more obstacles, andthen may lead back to the first trajectory. In some cases, theautonomous vehicle may validate the second trajectory prior to drivingaccording to the second trajectory.

FIG. 2 is a flow chart of method 200, according to an exampleembodiment. Method 200 may be carried out by an autonomous vehicle, suchas described below in the context of at least FIGS. 16 and 18.

At block 210, a determination may be made that a speed of an autonomousvehicle is less than or equal to a threshold speed and that theautonomous vehicle has not detected a traffic control signal, such asdiscussed below in more detail in the context of at least FIGS. 6 and 7.In some embodiments, determining that the speed of the autonomousvehicle is less than or equal to the threshold speed may includedetermining that the autonomous vehicle is not increasing speed. Thetraffic control signal may include be a stop sign signal, a stop lightsignal, a warning sign signal, and a warning light signal. The thresholdspeed may be between zero and one meter per second, between zero andthree meters per second, between zero and five meters per second, and soon.

At block 220, a cause C may be identified for the speed to be less thanor equal to the threshold speed, such as discussed below in more detailin the context of at least FIG. 7. In some embodiments, the cause C maybe based on a pedestrian, based on a vehicle other than the autonomousvehicle, and/or based on another type of object. The cause C mayobstruct a trajectory of the autonomous vehicle.

At block 230, a timer T that is based on the cause C may be started,such as discussed below in more detail in the context of at least FIG.7. At block 240, after the timer T expires, a determination may be madewhether the speed is still less than or equal to the threshold speedand/or the cause C remains as a cause for the speed to be less than orequal to the threshold speed, such as discussed below in more detail inthe context of at least FIG. 7. If this is the case, then, at block 250,an assistance signal indicating that the autonomous vehicle is stuck maybe sent from the autonomous vehicle, such as discussed below in moredetail in the context of at least FIG. 7.

In some embodiments, method 200 may further include, after sending theassistance signal, determining that the speed of the autonomous vehicleis greater than the threshold speed. Then, based on determining that thespeed of the autonomous vehicle is greater than the threshold speed, adetermination may be made that the autonomous vehicle is no longerstuck. In this case, the autonomous vehicle may no longer seek outassistance, and may transmit a message to the assistance centerindicating that the request for assistance is cancelled.

Method 200 may also include the autonomous vehicle receiving a responseto the assistance signal, where the response specifies a secondtrajectory for the autonomous vehicle, and navigating according to thesecond trajectory. The second trajectory may avoid the obstruction ofcause C. In particular embodiments, method 200 may further include,after navigating according to the second trajectory, determining thatthe autonomous vehicle may safely return to navigating according to thetrajectory. In response to determining that the autonomous vehicle mayreturn to navigating according to the trajectory, the autonomous vehiclemay switch from navigating according to the second trajectory tonavigating according to the trajectory.

FIG. 3 is a flow chart of method 300, according to an exampleembodiment. Method 300 may be carried out by an autonomous vehicle, suchas described below in the context of at least FIGS. 16 and 18.

At block 310, the autonomous vehicle may determine to seek assistance tonavigate in accordance with a first trajectory. The autonomous vehiclemay be configured to receive and store data about a plurality ofobstacles. A particular obstacle in the plurality of obstacles maypartially or wholly obstruct the first trajectory, such as discussedbelow in the context of at least FIGS. 5-17. In some embodiments, thestored data may include sensor data about the plurality of obstacles,where the sensor data may comprise representations of distances betweenthe autonomous vehicle and at least some obstacles in the plurality ofobstacles, such as discussed below in the context of at least FIGS.10-15C.

In full generality, one or more particular obstacles may obstruct thefirst trajectory. For instance, the autonomous vehicle may determinethat two, three, or more obstacles are obstructing its trajectory. Theautonomous vehicle may take action, in accordance with method 300 and/orany other embodiment herein, to navigate around or otherwise avoid theseobstacles. However, for sake of simplicity, some examples herein discusssuch processes in the context of a single obstacle.

At block 320, the autonomous vehicle may select a portion of the storeddata. The selected portion of the stored data may be less than thetotality of the stored data and may include data representing theparticular obstacle, such as discussed below in the context of at leastFIGS. 10 and 15A-15C. In some embodiments, the stored data may includevideo data about the plurality of obstacles. Then, selecting the portionof the stored data may include selecting at least some of the videodata, such as discussed below in the context of at least FIGS. 8, 10,and 15A-15C.

Selecting the portion of the stored data may include determining athreshold distance D. Then, for each obstacle O1 in the plurality ofobstacles, a distance D1 between the obstacle O1 and the autonomousvehicle may be determined. A further determination may be made whetherthe threshold distance D is greater than the distance D1. If thethreshold distance D is greater than the distance D1, the obstacle O1may be identified as a candidate obstacle for the portion of the storeddata. In particular embodiments, selecting the portion of the storeddata may include selecting stored data for each candidate obstacle.

In some embodiments, selecting the portion of the stored dataadditionally may include making a determination of a number N ofobstacles in the plurality of obstacles, where N>0. Then, for eachcandidate obstacle O2 in the plurality of obstacles, a determination maybe made whether the candidate obstacle O2 is one of N obstacles closestto the autonomous vehicle. If the candidate obstacle O2 is one of thenumber N obstacles closest to the autonomous vehicle, stored data aboutthe candidate obstacle O2 may be selected.

In further embodiments, selecting the portion of the stored data aboutthe plurality of obstacles may include determining a threshold distanceD2. Then, for each obstacle O1 in the plurality of obstacles, adetermination may be made of a closest distance value D3 between theobstacle O1 and a closest point on the original trajectory to O1. Theplurality of obstacles may be sorted based on the closest distancevalues D3. Stored data about for obstacles with a closest distance valueD3 less than the threshold distance D2 may be selected.

At block 330, the portion of the stored data may be provided to anassistance center, such as discussed below in the context of at leastFIGS. 10 and 15A-15C. In some embodiments, providing the portion of thestored data may include transmitting a request for navigationalassistance, receiving a request for information regarding obstacles, andtransmitting the portion of the stored data, such as discussed below inthe context of at least FIG. 10. This communication may take placebetween the autonomous vehicle and the assistance center.

At block 340, a second trajectory may be received from the assistancecenter. The second trajectory might not be obstructed by the particularobstacle, such as discussed below in the context of at least FIGS. 8-10and 15A-15C. In some embodiments, the second trajectory may meet thefirst trajectory at two or more points.

FIG. 4 is a flow chart of method 400, according to an exampleembodiment. Method 400 may be carried out by an assistance center, suchas described below in the context of at least FIG. 17.

At block 410, the assistance center may receive a representation of afirst trajectory of an autonomous vehicle that is in a stuck condition.The first trajectory might not relieve the stuck condition, such asdiscussed below in the context of at least FIGS. 8-10 and 15A-15C.

At block 420, the assistance center may receive sensor information ofthe autonomous vehicle, where the sensor information may includelow-level sensor strike input and high-level, polygonal or polyhedralrepresentations of objects in the vicinity of the autonomous vehicle.The high-level, polygonal or polyhedral representations of objects maybe based at least in part on the low-level sensor strike input, such asdiscussed below in the context of at least FIGS. 8-10 and 15A-15C.

At block 430, the assistance center may, based on the first trajectoryand the sensor information, determine a second trajectory that relievesthe stuck condition while adhering to at least some navigationalconstraints. These navigational constraints may include, for instance,the autonomous vehicle avoiding collisions, obeying traffic laws, and/ornot causing inertial discomfort to its passengers. Relieving the stuckcondition may include ignoring at least one high-level, polygonal orpolyhedral representation of an object that obstructs the firsttrajectory, such as discussed below in the context of at least FIGS.8-10 and 15A-15C. In some embodiments, the first and second trajectoriesmay be identical.

Determining the second trajectory may include determining that the firsttrajectory does not relieve the stuck condition. After determining thatthe first trajectory does not relieve the stuck condition, the secondtrajectory may be determined such that the second trajectory isdifferent from the first trajectory and the second trajectory intersectsthe first trajectory at two or more points.

Alternatively or additionally, determining the second trajectory mayinclude receiving a request for navigational assistance from theautonomous vehicle, transmitting a request for additional informationfrom the assistance center to the autonomous vehicle, and receiving aproposed trajectory from the autonomous vehicle. The second trajectorymay be based on the proposed trajectory, and the proposed trajectory mayintersect the first trajectory at two or more points. In some of theseembodiments, the second trajectory and the proposed trajectory may beidentical, perhaps indicating that the assistance center has acceptedthe proposed trajectory.

In yet other embodiments, the second trajectory may be determinedwithout human interaction. In still other embodiments, the secondtrajectory may be determined using a computing device at the assistancecenter, where the computing device is coupled to a graphical userinterface configured to display autonomous vehicle trajectories, andwhere at least some of the second trajectory may be defined using thegraphical user interface.

Method 400 may further include determining that the proposed trajectoryrelieves the stuck condition. Method 400 may additionally includedetermining that the proposed trajectory does not relieve the stuckcondition, and modifying the proposed trajectory so that the modifiedproposed trajectory relieves the stuck condition. In these cases, thesecond trajectory may be the modified proposed trajectory.

At block 440, the assistance center may transmit a representation of thesecond trajectory and instructions for the autonomous vehicle to drivein accordance with the second trajectory, such as discussed below in thecontext of at least FIGS. 8-10 and 15A-15C.

In embodiments where the second trajectory is determined using acomputing device at the assistance center, method 400 may furtherinclude estimating a network data rate between the autonomous vehicleand the computing device and requesting that the autonomous vehicletransmit location and sensor information to the assistance center suchthat the estimated data rate is not exceeded. This may involveestimating, or otherwise determining a maximum network data rate betweenthe autonomous vehicle and the computing device and controlling theactual data rate between autonomous vehicle and the computing device sothat it is no greater than the maximum data rate.

To that point, FIG. 5 shows an example autonomous vehicle operatingenvironment 500 with a number of autonomous vehicles 510, 512, 514 incommunication with assistance center 520 via network 522. In someembodiments, some or all of autonomous vehicles 510, 512, 514 may becapable of communicating with assistance center 520. Network 522 mayinclude one or more networks, such as, but not limited to, one or morewireless wide area networks (WWANs) and/or wireless local area networks(WLANs). Each of autonomous vehicles 510, 512, 514 may be configuredwith a communication component at least for communicating withassistance center 520 and network 522. Also, assistance center 520 maybe configured with a communications component for communicating with oneor more of autonomous vehicles 510, 512, 514 and network 522. In someembodiments, some or all functions of assistance center 520 may beperformed in an autonomous vehicle, perhaps by a human rider or driver.

FIG. 6 shows an example scenario 600 where an autonomous vehicle 610 isattempting to drive on road 602 according to original trajectory 630 todestination 632. However, autonomous vehicle 610 is in a stuck conditionbecause original trajectory 630 is blocked by vehicle 614. Thus,navigation according to original trajectory 630 is not possible withoutadjusting a destination or trajectory of autonomous vehicle 610.Autonomous vehicle 602 may be configured to be able to drive on a leftlane of road 602. However, in scenario 600, vehicle 612 blocks thattrajectory. In scenario 600, vehicles 612, 614, 616, and 618 may bestopped or moving at a slow speed.

FIG. 7 shows an example method 700 for detecting whether an autonomousvehicle is in a stuck condition. At block 710, the autonomous vehiclemay determine if it is either increasing speed and/or if a current speedof the autonomous vehicle is greater than a threshold speed of X metersper second (m/s). In some embodiments, X may be specified in dimensionsother than meters per second; e.g., miles per hour, kilometers per hour,or feet per second. If the autonomous vehicle is either increasing speedor if the current speed of the autonomous vehicle is greater than Xmiles per hour, the autonomous vehicle is not stuck. In some cases, theautonomous vehicle may only determine whether its current speed isgreater than the threshold speed.

Otherwise, at block 720, the autonomous vehicle may determine whether ithas detected a traffic control signal. The traffic control signal mayinclude a stop sign signal, a stop light signal, a warning sign signal,a warning light signal, yield signal, or some other type of signal thatmay indicate that the autonomous vehicle should be stopped or operatingat a limited speed. If the autonomous vehicle has detected a trafficcontrol signal, the autonomous vehicle is not stuck. Nonetheless, if anautonomous vehicle has been stationary or moving slowly in the presenceof a traffic control signal for more than a threshold period of time,the autonomous vehicle may consider itself to be stuck. For instance,the autonomous vehicle may be stopped at a stop sign with its trajectoryblocked by another vehicle.

Otherwise, at block 730, the autonomous vehicle may determine whether itis currently stopped awaiting user input. For example, the autonomousvehicle may be stopped while a user specifies a destination for theautonomous vehicle. If the autonomous vehicle is stopped awaiting userinput, the autonomous vehicle is not stuck.

Otherwise, at block 740, the autonomous vehicle may identify a cause Cfor the autonomous vehicle not to be increasing speed and/or for thecurrent speed less than or equal to the threshold speed. The cause C maybe a cause based on a pedestrian, a cause based on a vehicle other thanthe autonomous vehicle, or a cause based on a particular type of objector an unknown object.

At block 750, the autonomous vehicle may set a timer T for T1 seconds,where T1 is based on the cause C. Table 1 below shows an example tableof causes and corresponding T1 values.

TABLE 1 Cause T1 Vehicle  8 seconds Pedestrian 18 seconds Unknown objectin trajectory 12 seconds

In some embodiments, additional causes to those shown in Table 1 may beidentified by the autonomous vehicle, and consequently additional T1values may be associated with the additional causes. In some cases, T1values may differ from those specified in Table 1.

Alternatively or additionally, T1 values may be a function of blockagedata for a location, where the autonomous vehicle may be stuck due tothe nature of the location. For example, T1 values may be determinedusing a decision tree such as shown in Table 2 below:

TABLE 2 1. Has the autonomous vehicle traversed this locationpreviously? a. Yes - have any vehicular obstacles been encountered atthis location? i. Yes - has a vehicular obstacle been reported within athreshold period oftime; e.g., 15 minutes? 1. Yes - set T1 = T1 valueused for previous obstacle 2. No - set T1 = 10 seconds ii. No - is theblockage in the curbside lane? 1. Yes - set T1 = 12 seconds. 2. No - setT1 = 15 seconds. b. No - is the blockage in the curbside lane? i. Yes -set T1 = 12 seconds. ii. No - set T1 = 15 seconds.

In even other embodiments, T1 may be specified based on a combination offeatures including, but not limited to:

-   -   a day of week—e.g., useful for taking into account events like        street cleaning days, working days, non-working days/holidays;    -   property usage information—e.g., is the vehicle at or near        building(s) where traffic may have fairly regular patterns, such        as a school, a university, a factory, a hospital, a stadium or        arena, an office campus, etc.;    -   a time of day—e.g., schools tend to cause more blockages in the        morning and early afternoon, factories and hospitals may have        increased traffic at shift changing times, arenas may have        increased traffic before and after an event; and/or    -   a number of autonomous vehicles passing through this location        per unit time as a measure of congestion.    -   a number of non-autonomous vehicles passing through this        location per unit time as a measure of congestion.

In still other embodiments, T1 may be specified using other units oftime than seconds; e.g., tenths of seconds or minutes.

At block 752, timer T may run for T1 seconds; e.g., timer T may bestarted by the autonomous vehicle. At block 760, the autonomous vehiclemay wait for timer T to expire; i.e., wait for at least T1 seconds.

At block 770, the autonomous vehicle may determine whether it is notincreasing speed and/or cause C remains as the cause for the autonomousvehicle not to be increasing speed. If cause C does not remain, then theautonomous vehicle is no longer stuck. In some cases, there may bemultiple causes for the autonomous vehicle to be stuck. Thus, theautonomous vehicle may examine its environment for another cause, andmay attempt to address any further cause in accordance with thetechniques described herein.

At block 780, the autonomous vehicle may determine that it is in a stuckcondition and send an alert, such as an assistance signal, to indicatethat the autonomous vehicle is stuck. In some embodiments, aftercompleting block 780, method 700 may restart; e.g., method 700 mayproceed to block 710.

Alternatively or additionally, the autonomous vehicle may process, inparallel, several causes that overlap in time. For instance, if theautonomous vehicle determines that there is another vehicle stopped infront of it and a pedestrian is also crossing the road in front of it,the autonomous vehicle may start two independent timers, one for theother vehicle and one for the pedestrian. If either timer expires, theautonomous vehicle may determine that it is in a stuck condition.

At block 790, the autonomous vehicle may determine that it is not in astuck condition. In some embodiments, the autonomous vehicle may send analert to the assistance center. This alert may be a “clear path” signal,to indicate that the autonomous vehicle is not stuck. In someembodiments, after completing the techniques of block 790, method 700may restart; e.g., method 700 may proceed to block 710.

FIG. 8 shows an example scenario 800 where an autonomous vehicle 810 isattempting to drive on road 802 following original trajectory 830 todestination 832. However, autonomous vehicle 810 is in a stuck conditionsince original trajectory 830 is blocked by vehicle 814. In examplescenario 800, vehicles 812, 814, 816, and/or 818 may be stopped ormoving slowly (e.g., below a threshold speed).

Upon recognizing that it is in the stuck condition, autonomous vehicle810 may send (perhaps wirelessly) an assistance signal to an assistancecenter (not shown in FIG. 8) to relieve the stuck condition. Theassistance center may accept the assistance signal and requestadditional data from autonomous vehicle 810. Alternatively, autonomousvehicle 810 may provide the additional data to the assistance centerbefore receiving such a request.

As mentioned above, heuristics may be applied to reduce the volume ofdata. One heuristic is to organize the obstacles by distance from theautonomous vehicle and/or to cap the number of obstacles to be the Onearest. Doing so may filter out any obstacles more than D meters away.For example, FIG. 8 shows that vehicle 814 is nearest to autonomousvehicle 810, and then vehicle 812, bottles 820, 822, 824, 826, and 828,and then vehicles 816 and 818. In some embodiments, D may be a functionof the speed of autonomous vehicle 810; i.e., the faster the speed ofautonomous vehicle 810, the larger the distance that should beconsidered. Thus, D may increase (or decrease) as the speed ofautonomous vehicle 810 increases (or decreases).

Another heuristic may involve sorting obstacles by their distance fromthe nearest point on the trajectory of autonomous vehicle 810. Computingthis set of obstacles may provide a more useful view of upcomingobstacles by prioritizing obstacles in the front of autonomous vehicle810, but deprioritizing obstacles behind or off to the sides ofautonomous vehicle 810. For example, with respect to new trajectory 836,FIG. 8 shows that new trajectory 836 comes closest to vehicle 814, thenvehicles 816 and 812, bottles 820, 822, 824, 826, and 828, and thenvehicle 818.

Even another heuristic is to prefer expert-friendly types of data fortransmission. For example, human experts often may quickly analyze acondition of autonomous vehicle 810 using video data, or if video datais unavailable, using recent still images. Autonomous vehicle 810 maypreferentially transmit video data (or still images) over other types ofdata, as this data is more likely to lead to resolution of the stuckcondition than other types of data. In addition to these heuristics toreduce transmission load, throttling (i.e., only transmitting data everyX seconds, or when there is a meaningful change) may also be used tofurther reduce load. Some or all of the herein-described heuristics maybe used by autonomous vehicle 810 to provide data to the assistancecenter.

After receiving this data at the assistance center, an expert maypropose new trajectory 836, which begins at a current position ofautonomous vehicle 810 and finishes at endpoint 838, where newtrajectory 836 joins original trajectory 830. (It is assumed thatautonomous vehicle 810 can navigate according to new trajectory 836without colliding with any objects—thus, FIG. 8, and possibly otherfigures as well, may not be drawn to scale.)

Upon reaching endpoint 838, autonomous vehicle 810 may switch from newtrajectory 836 to original trajectory 830. After receiving and possiblyvalidating new trajectory 836, autonomous vehicle 810 may driveaccording to new trajectory 836 to endpoint 838 and then according tooriginal trajectory 830 to destination 832. In some embodiments,endpoint 838 might not be on original trajectory 830. Instead, endpoint838 may allow autonomous vehicle 810 to proceed to a location that maypartially relieve the stuck condition. From this location, autonomousvehicle 810 may calculate and/or drive according to one or moreadditional trajectories that may result in autonomous vehicle 810eventually rejoining original trajectory 830.

FIG. 9 shows an example scenario 900 where autonomous vehicle 810 isattempting to drive on road 902 following original trajectory 930 todestination 932. Road 902 is similar to road 802 of FIG. 9. However,road 902 has shoulders 904, 906 while road 802 does not have shoulders.Associated with road 902 is sign 910 indicating that “SHOULDER RIDING”is “ALLOWED”. In example scenario 900, vehicles 812, 814, 816, and/or818 may be stopped or moving slowly (e.g., below a threshold speed).

Scenario 900 shows that original trajectory 830 is blocked by vehicle814. Although autonomous vehicle 810 may be permitted to drive on a leftlane of road 902, vehicle 812 blocks that trajectory. Thus, autonomousvehicle 810 may be in a stuck condition.

In scenario 900, upon recognizing that it is in the stuck condition,autonomous vehicle 810 may send an assistance signal to an assistancecenter (not shown in FIG. 9) to relieve the stuck condition. As part ofthe assistance signal or in another communication, autonomous vehicle810 may provide proposed trajectory 936 to the assistance center forconsideration. For example, scenario 900 may have occurred afterscenario 800 and autonomous vehicle 810 may have stored trajectory 836.Thus, autonomous vehicle 810 may have considered trajectory 836 for usein scenario 900 (possibly with slight modifications as bottles 820, 822,and 824 are slightly farther from vehicle 810), and proposed trajectory936 based on the slightly-modified trajectory 836. As shown in FIG. 9,proposed trajectory 936 may rejoin original trajectory 930 at proposedendpoint (PEP) 938.

Upon receiving the assistance signal, the assistance center may requestand subsequently receive additional information about autonomous vehicle810 and its environment. In particular, an expert at the assistancecenter may be provided with image(s) and/or other information about sign910, and so learn that shoulder riding is allowed. Then, the expert mayexamine information about shoulder 906 and determine that new trajectory946 taking shoulder 906 may be used by autonomous vehicle 810 to bypassvehicle 814. As shown in FIG. 9, new trajectory 946 may rejoin originaltrajectory 930 at new endpoint (NEP) 948. New trajectory 946 has anadvantage of generally keeping autonomous vehicle 810 further fromobstacles. Therefore, the assistance center may reject proposedtrajectory 936 in favor of new trajectory 940.

In providing new trajectory 946 to autonomous vehicle 810, theassistance center may provide a temporary override of any rulesinhibiting autonomous vehicle 810 from shoulder riding at least whiletraveling on new trajectory 946. In scenario 900, autonomous vehicle 810may receive new trajectory 946 with a temporary override allowingshoulder riding, verify new trajectory 946, and request the assistancecenter confirm new trajectory 946. Then, the assistance center mayconfirm new trajectory 946. Upon receiving confirmation of newtrajectory 946, autonomous vehicle 810 may take new trajectory 946 tonew endpoint 948. At new endpoint 948, autonomous vehicle 810 may rejoinoriginal trajectory 930, and drive to destination 932, in accordance tooriginal trajectory 930.

FIG. 10 is a flow chart of an example method 1000 that could be used inconjunction with either method 800, method 900, or other methodsdisclosed herein or defined elsewhere. In example method 1000,autonomous vehicle 1010 may request assistance from assistance center520 to relieve a stuck condition. For instance, autonomous vehicle 1010may determine that it is in a stuck condition and send assistance signal1022 to assistance center 520. After receiving assistance signal 1022,assistance center 520 may send request 1024 to connect to autonomousvehicle 1010.

At block 1026, after connecting to autonomous vehicle 1010, an expert atassistance center 520 may assess a state of autonomous vehicle 1010. Theexpert may be a human expert, an expert system and/or other computercomponents, and/or a combination of human expert(s) and computercomponent(s).

At block 1030, the expert at assistance center 520 may determine whetheror not assistance center 520 is to intervene with the navigation ofautonomous vehicle 1010. If the expert at assistance center 520determines to intervene, then assistance center 520 may send request1032 to enter augmented mode. During augmented mode, autonomous vehicle1010 may provide additional data to assistance center 520. Thisadditional data may be a combination of location and sensor data fromthe autonomous vehicle.

At block 1040, autonomous vehicle 1010 may determine whether it shouldenter augmented mode. For example, autonomous vehicle 1010 may determinewhether enough network capacity is available to transmit the necessarydata, and/or perform other checks to determine whether or not augmentedmode may be entered.

If autonomous vehicle 1010 determines that it should enter augmentedmode, then autonomous vehicle 1010 may (periodically or from time totime) send additional data 1044 to assistance center 520. Autonomousvehicle 1010 may apply one or more heuristics to determine additionaldata 1044 prior to sending. Additional data 1044 may include low-levelperceptual data about obstacles, high-level perceptual data aboutobjects, video data, still images, location data and/or audio data.Further, as previously discussed, this additional data may be a subsetof all environmental data available to autonomous vehicle 1010,selecting according to, for instance, relative importance.

In some embodiments, at block 1050, autonomous vehicle 1010 may proposea trajectory to relieve the stuck condition. The proposed trajectory mayinclude a path from a current position of autonomous vehicle 1010 to anendpoint where the proposed trajectory joins an original trajectory thatautonomous vehicle 1010 was utilizing prior to entering the stuckcondition. Alternatively, endpoints that are not on the originaltrajectory may be used.

Autonomous vehicle 1010 may send proposed trajectory 1052 to assistancecenter 520. At block 1054, the expert at assistance center 520 maydetermine whether or not proposed trajectory 1052 relieves the stuckcondition while adhering to the navigational constraints of autonomousvehicle 1010. These navigational constraints may include, for instance,the autonomous vehicle avoiding collisions, obeying traffic laws, and/ornot causing inertial discomfort to its passengers. If the expert atassistance center 520 determines that this is the case, assistancecenter 520 may send confirmation 1056 of proposed trajectory 1052 toautonomous vehicle 1010.

If the expert at assistance center 520 determines that this is not thecase, the expert at assistance center 520 may devise a trajectory torelieve the stuck condition. For example, the expert may modify anexisting plan, modify a solution provided by autonomous vehicle 1010, orgenerate a new plan in order to devise the trajectory. The devisedtrajectory may include a path from the current position of autonomousvehicle to an endpoint where the devised trajectory joins the originaltrajectory of autonomous vehicle 1010, or to some other endpoint.Assistance center 520 may send devised trajectory 1062 to autonomousvehicle 1010.

At block 1064, autonomous vehicle 1010 may receive a representation oftrajectory T, which may be either proposed trajectory 1052 or devisedtrajectory 1062. At block 1066, autonomous vehicle 1010 may determinewhether or not it may follow trajectory T to relieve the stuckcondition. For example, autonomous vehicle 1010 may determine thatautonomous vehicle 1010 may actually execute the trajectory T withoutviolating any rules of operation for autonomous vehicle 1010; e.g.,traffic laws. As another example, autonomous vehicle 1010 may rechecklocations of objects to verify that trajectory T will likely not lead toa collision.

If autonomous vehicle 1010 determines that it may follow trajectory T,autonomous vehicle 1010 may send final confirmation request 1070 fortrajectory T. In some scenarios, autonomous vehicle 1010 may not be ableto confirm trajectory T, for instance, due to a lack of sensor dataregarding the safety of trajectory T. In these scenarios, autonomousvehicle 1010 may send a message to assistance center 520 rejectingtrajectory T, perhaps including one or more reasons for rejectingtrajectory T.

At block 1072, the expert at assistance center 520 may verify thattrajectory T is valid; e.g., that trajectory T may relieve the stuckcondition without violating the navigational constraints of autonomousvehicle 1010. If the expert at assistance center 520 verifies trajectoryT, assistance center 520 may send confirmation 1080 of trajectory T toautonomous vehicle 1010. At block 1090, autonomous vehicle 1010 maydrive according to trajectory T, to an endpoint of trajectory T, torelieve the stuck condition.

As autonomous vehicle 1010 drives according to trajectory T, autonomousvehicle 1010 may continue to receive new environmental data, such as newlaser strike data. In cases where this new environmental data indicatesthat autonomous vehicle 1010 cannot follow trajectory T, autonomousvehicle 1010 may respond accordingly. For instance, based on the natureof the new environmental data, autonomous vehicle 1010 may avoid newobstacles, or once again determine that it is stuck. In this way,autonomous vehicle 1010 may avoid blindly following a trajectory whendoing so puts autonomous vehicle 1010 at risk of colliding with anotherobject.

Nonetheless, low-level data, such as clusters of laser strikes onsurfaces in the vicinity of the autonomous vehicle, may be useful to theassistance center. FIG. 11 schematically illustrates a LIDAR unit 1102,perhaps mounted to, attached to, or part of an autonomous vehicle,scanning across an obstacle-filled environment. The example environmentdepicted in FIG. 11 includes a car 1110 and a tree 1112.

In operation, LIDAR unit 1102 may rotate according to motion referencearrow 1108 with angular velocity ω. While rotating, LIDAR unit 1102regularly (e.g., periodically or from time to time) emits laser beams,such as a laser beam 1106. Reflections from the emitted laser beamscaused by objects in the environment, such as the car 1110 and the tree1112, may be received by suitable sensors associated with LIDAR unit1102. Time-stamping the receipt of the reflected signals allows forassociating each reflected signal (if any is received at all) with themost recently emitted laser pulse, and measuring the time delay betweenemission of the laser pulse and reception of the reflected light.

The time delay provides an estimate of the distance to the reflectivefeature by scaling according to the speed of light in the interveningatmosphere. Combining the distance information for each reflected signalwith the orientation of LIDAR unit 1102 for the respective pulseemission allows for determining a position of the reflective feature inthree-dimensions.

In some embodiments, LIDAR unit 1102 may be configured to capture one ormore laser point clouds of the environmental scene at predetermined timeintervals, such as 100 milliseconds (for a refresh rate of 10 frames persecond), 33 milliseconds (for a refresh rate of 30 frames per second), 1millisecond, 1 second, etc.

In some embodiments, a single laser in LIDAR unit 1102 may have ascanning range of approximately 150 meters distance, a thirty degreevertical (“altitude”) field of view, and approximately a thirty degreehorizontal (“azimuth”) field of view. Additional lasers included inLIDAR unit 1102 may have complementary ranges and fields of view as wellso as to provide sufficient coverage of an environmental scene to informnavigational determinations.

FIG. 12 schematically illustrates an example point cloud correspondingto the obstacle-filled environmental scene of FIG. 11. Spatial-pointdata (represented by stars) are shown from a ground-plane (or aerial)perspective. Even though the individual points are not equallydistributed in space throughout the sampled environment, adjacentsampled points are roughly equally spaced angularly with respect toLIDAR unit 1102. In some embodiments, point clouds may have as many as50,000 laser-indicated points, 80,000 laser-indicated points, 100,000laser-indicated points, etc. More or fewer laser-indicated points may beused.

Car spatial data 1214 may correspond to measured points on the surfaceof car 1110 with a line of sight to LIDAR unit 1102. Similarly, treespatial data 1216 may correspond to measured points on the surface oftree 1112 visible from LIDAR unit 1102. The absence of points betweencar spatial data 1214 and tree spatial data 1216 indicates an absence ofreflective features along the sampled line of sight paths in the planeillustrated.

Each point in the example point cloud illustrated in FIG. 12 may bereferenced by an azimuth angle ϕ (e.g., the orientation of LIDAR unit1102 while emitting the pulse corresponding to the point), which isdetermined by the orientation of a rotating angled mirror (not shown) ofLIDAR unit 1102 and a line-of-sight (LOS) distance (e.g., the distanceindicated by the time delay between pulse emission and reflected lightreception). For emitted pulses that do not receive a reflected signal,the LOS distance may optionally be set to the maximum distancesensitivity of LIDAR unit 1102. The maximum distance sensitivity may bedetermined according to the maximum time delay the associated opticalsensors wait for a return reflected signal following each pulseemission, which may itself be set according to the anticipated signalstrength of a reflected signal at a particular distance given ambientlighting conditions, intensity of the emitted pulse, predictedreflectivity of environmental features, etc. In some examples, themaximum distance may be approximately 60 meters, 80 meters, 100 meters,or 150 meters, but other examples of maximum distance are possible forparticular configurations of LIDAR unit 1102 and associated opticalsensors.

In some embodiments, car spatial data 1214 may be low-level “strikeinput” data. This low-level data may be considered alone and/or incombination with additional sensor-indicated information, memory-basedpattern-matching point clouds, and/or baseline maps of the environmentto generate high-level, polygonal or polyhedral representations ofobjects in the environment. The high-level, polygonal or polyhedralrepresentations may be generated by categorizing or identifying carspatial data 1214 as corresponding to car 1110 and generating apolygonal or polyhedral representation of car 1110. Similarly, treespatial data 1216 may identified as corresponding to tree 1112 inaccordance with a suitable object-detection technique and so lead togeneration of a polygonal or polyhedral representation of tree 1112.

This processing may make use of an object detector. An object detectormay be any configuration of software and/or hardware configured toperceive features in the environmental scene by categorizing object(s),identifying object(s), and/or generating polygonal or polyhedralrepresentation(s) of categorized/identified objects based on thelow-level laser point clouds captured by LIDAR unit 1102 and/or based onone or more of the sensors in the sensor system 1604. As a laser pointcloud is captured via LIDAR unit 1102, data indicative of the capturedpoint cloud is communicated to the object detector, which analyzes thedata to determine whether there is an object present in the laser pointcloud. Objects indicated by the point cloud may be, for example, avehicle (e.g., car 1110) an obstacle (e.g., tree 1112), a pedestrian, aroad sign, a traffic light, a traffic cone, etc.

To determine whether an object is present in a laser point cloud image,the object-detector software and/or module may associate arrangements oflaser-indicated points with patterns matching objects, environmentalfeatures, and/or categories of objects or features. The object detectormay be pre-loaded (or dynamically instructed) to associate arrangementsaccording to one or more parameters corresponding to physicalobjects/features in the environment surrounding vehicle 1110. Forexample, the object detector may be pre-loaded with informationindicating a typical height of a pedestrian, a length of a typicalautomobile, confidence thresholds for classifying suspected objects,etc.

If an object (or objects) is present in the point cloud, the objectdetector may generate a polygonal or polyhedral representationcorresponding to the object. For example, when the object detectoridentifies an object in a point cloud, the object detector may define abounding box encompassing the object. The bounding box may correspond toa predicted exterior surface of the point cloud indicated object. Ofcourse, the bounding “box” may generally take the form of a multi-sidedpolygon or polyhedron defining the predicted outer boundaries of theobject.

For each captured point cloud, positions of perceived objects and theircorresponding boundary definitions are associated with a frame number orframe time. Thus, similarly shaped objects appearing in the same orroughly similar locations in successive scans of the scene may beassociated with one another to track objects in time. Perceived objectsappearing in multiple point cloud frames (e.g., complete scans of thescanning zone), may be considered to be the same object, and may beeither stationary or in motion relative to vehicle 1110. Each perceivedobject may be associated, for each frame on which the perceived objectappears, with a distinct bounding shape defining the dimensional extentof the perceived object.

Further, as noted above, each spatial point may be associated with arespective laser from a set of lasers and a respective timestamp. Thatis, in an embodiment where LIDAR unit 1102 includes multiple lasers,each respective spatial point may be associated with the particularlaser that detected the respective spatial point. Additionally, eachrespective spatial point may be associated with a respective timestamp(e.g., a time at which the particular laser was emitted or received). Inthis way, the received spatial points may be organized, identified, orotherwise ordered on a spatial (laser identification) and/or temporal(timestamp) basis. Such an ordering may assist or improve an analysis ofthe spatial point data by allowing for organizing the spatial point datainto a meaningful order. Some or all of the laser strike data, pointcloud data, and/or object-related bounding box data may be stored by theautonomous vehicle.

FIG. 13 schematically illustrates spatial point data indicative of asurface of a target vehicle that is stationary relative to a LIDAR unit,according to an example embodiment. The LIDAR unit may be mounted on anautonomous vehicle or otherwise integrated or associated with anautonomous vehicle. In this example, a target surface 1318 is identifiedfrom a set of spatial points indicative of locations of reflectivesurfaces received from LIDAR unit 1102 by an object-detection techniquementioned herein and/or any other known or later developed. In someembodiments, the set of spatial points is received from a single sweepof LIDAR unit 1102. Target surface 1318 may be a front or rear surfaceof a target vehicle, such as vehicle 1110.

In this example, a first point 1320 and a second point 1326 are alsoidentified by an object-detection technique mentioned herein and/or anyother known or later developed. The first point 1320 is indicative of afirst location 1322 on target surface 1318 obtained from LIDAR unit 1102at a first time 1324, and the second point 1326 is indicative of asecond location 1328 on target surface 1318 obtained from LIDAR unit1102 at a second time 1330. Other points illustrated in FIG. 13 may beindicative of other locations on target surface 1318 obtained from LIDARunit 1102 at other times. With this arrangement, a speed of targetsurface 1318 relative to LIDAR unit 1102 may be estimated based on thefirst location 1322, the first time 1324, the second location 1328, andthe second time 1330.

In this example, the estimate of a relative speed of target surface 1318may be determined based on an offset between first location 1322 andsecond location 1328 divided by a time difference between the secondtime 1330 and the first time 1324.

As illustrated in FIG. 13, a coordinate frame 1332 includes alongitudinal axis 1334. In this example, target surface 1318 isperpendicular to the longitudinal axis 1334. A projected first point1336 may be determined by projecting the first point 1320 onto thelongitudinal axis 1334, and a second point 1338 may be determined byprojecting the second point 1326 onto the longitudinal axis 1334. Withthis arrangement, the offset between the first location 1322 and thesecond location 1328 is determined as a distance between the projectedfirst point 1336 and the projected second point 1338.

In this example, the offset is zero because the projected first point1336 and the projected second point 1338 are each at the same locationon the longitudinal axis 1334. Accordingly, the estimate of the speed oftarget surface 1318 in this example is zero.

In some embodiments, the coordinate frame 1332 may include a fixedcoordinate frame in an environment of LIDAR unit 1102 based on data froman inertial measurement unit (IMU) associated with a vehicle. However,in some embodiments, the defining of a coordinate frame may also bebased at least in part on data from other sensors associated with thevehicle. For instance, the defining of a coordinate frame may also bebased at least in part on data from a GPS associated with the vehicle.Doing so may improve estimates of the speed and trajectory of targetsurface 1318. Other examples are also possible.

In some embodiments, the longitudinal axis 1334 may be defined based ona direction of motion of LIDAR unit 1102 and/or a direction of motion oftarget surface 1318. In some examples, the direction of motion of LIDARunit 1102 is known. However, in other examples, the direction of motionof LIDAR unit 1102 may be identified based on any technique mentionedherein and/or any other known or later developed. For instance, thedirection of motion of LIDAR unit 1102 may be identified based on adirection of a path that LIDAR unit 1102 is traveling, such as a roadwayor a traffic lane. In some examples, the direction of motion of targetsurface 1318 is known. However, in other examples, the direction ofmotion of target surface 1318 may be identified based on any techniquementioned herein and/or any other known or later developed.

FIG. 14 schematically illustrates spatial point data indicative of asurface of a target vehicle that is moving relative to the LIDAR unit,according to an example embodiment. In this example, a first point 1440and a second point 1446 on target surface 1318 are also identified by anobject-detection technique discussed herein and/or any others known orlater developed. First point 1440 is indicative of a first location 1442on target surface 1318 obtained from LIDAR unit 1102 at a first time1444, and second point 1446 is indicative of a second location 1448 ontarget surface 1318 obtained from LIDAR unit 1102 at a second time 1450.Other points illustrated in FIG. 14 may be indicative of other locationson target surface 1318 obtained from LIDAR unit 1102 at other times.

In this example, target surface 1318 has a known direction of motion1458. Further, an estimate of a speed of target surface 1318 may bedetermined based on an offset between first location 1442 and secondlocation 1448 divided by a time difference between second time 1450 andfirst time 1444.

A projected first point 1452 may be determined by projecting first point1440 onto longitudinal axis 1334, and a projected second point 1454 maybe determined by projecting second point 1446 onto longitudinal axis1334. With this arrangement, the offset between first location 1442 andsecond location 1448 may be determined as a distance between projectedfirst point 1452 and projected second point 1454. The offset is greaterthan zero because projected first point 1452 and projected second point1454 are separated by a non-zero distance on longitudinal axis 1334.Accordingly, the estimate of the speed of target surface 1318 is greaterthan zero. As illustrated in FIG. 14, the distance may represent alongitudinal distance traveled 1456 by target surface 1318.

FIGS. 15A, 15B, and 15C show scenario 1500 using trajectory userinterface (UI) 1510 to relieve a stuck condition of an autonomousvehicle. In some embodiments, trajectory UI 1510 may be provided using agraphical user interface (GUI) of a computing device. For example,trajectory UI 1510 may utilize one or more windows, buttons, dialogs,and other components of the GUI. In scenario 1500, trajectory UI 1510may be utilized at an assistance center, such as assistance center 520,and may be configured to communicate with one or more autonomousvehicles and with one or more experts. The expert(s) may be humanexperts and/or computing components, such as but not limited to expertsystems. Alternatively or additionally, trajectory UI 1510 may beutilized in an autonomous vehicle, perhaps by a passenger of theautonomous vehicle.

FIG. 15A shows a display of trajectory UI 1510 including an autonomousvehicle/data selection section 1511, autonomous vehicle display 1520,and a display control section 1570. In some embodiments, more, less, ordifferent sections and/or displays may be provided using trajectory UI1510.

Autonomous vehicle/data selection section 1511 includes autonomousvehicle selection button 1512, video data button 1514, low-level databutton 1516, and high-level data button 1518. In some embodiments, more,less, or different buttons may be provided in the autonomousvehicle/data selection section of trajectory UI 1510.

In FIGS. 15A-15C, buttons that are selected are shown with a graybackground, while buttons that are not selected are shown with a whitebackground. For example, in scenario 1500, high-level data button 1518is selected, while autonomous vehicle selection button 1512, video databutton 1514 and low-level data button 1516 are not selected.

Upon selection, autonomous vehicle selection button 1512 may instructtrajectory UI 1510 to display a dialog or similar graphical component(not shown in the figures) listing autonomous vehicles seekingassistance. An expert may use the dialog to select an autonomous vehicleto assist, and upon selection, begin communication with the selectedautonomous vehicle. Once an autonomous vehicle is selected forassistance, trajectory UI 1510 may display an identifier and/or otherinformation for the selected autonomous vehicle. FIG. 15A shows anidentifier “AV×123” for an autonomous vehicle selected for assistanceduring scenario 1500. Then, when the expert has finished assisting theselected autonomous vehicle, the expert may use autonomous vehicleselection button 1512 to select another autonomous vehicle to beassisted, assuming that another autonomous vehicle has requestedassistance.

Video data button 1514, when selected, may be used to generate a requestto a selected autonomous vehicle to provide video data. The video datamay include sequences of images configured for display in succession ata constant rate and/or still images. Once video data is available,trajectory UI 1510 may display the video data using autonomous vehicledisplay 1520 and/or using another display or window. In someembodiments, if more than one of buttons 1514, 1516, and 1518 areselected, separate displays or windows may be provided by trajectory UI1510 for each type of data; e.g., video data associated with button1514, low-level data associated with button 1516, and high-level dataassociated with button 1514. Low-level data and high-level data arediscussed below in more detail at least in the context of FIG. 16.Alternatively or additionally, some or all of video data, low-leveldata, and high-level data may be combined into one display.

Low-level data button 1516, when selected, may generate a request to aselected autonomous vehicle to provide low-level data. When thelow-level data is available, the low-level data may be displayed usingautonomous vehicle display 1520 and/or using another display or window.High-level data button 1518, when selected, may generate a request to aselected autonomous vehicle to provide high-level data. When thehigh-level data is available, the high-level data may be displayed usingautonomous vehicle display 1520 and/or using another display or window.

In some embodiments, the autonomous vehicle selects data fortransmission to the assistance center. In these embodiments, selectionof one of buttons 1514, 1516, or 1518 may not lead to a request fordata; rather, trajectory UI 1510 may indicate that such data isavailable by changing display of buttons 1514, 1516, and/or 1518 toindicate data availability. Then, if the expert selects a buttonassociated with available data, the data may be displayed usingautonomous vehicle window 1520 or another window. And, upon selection ofa button not associated with available data, an error message/dialog maybe generated indicating the unavailability of the selected data. Inparticular embodiments, even if the autonomous vehicle selects data fortransmission, the autonomous vehicle may honor a request for data, andin these embodiments, upon selection of a button not associated withavailable data, a request for the data may be sent to the autonomousvehicle.

In scenario 1500, high-level data is provided by the autonomous vehicleand is selected, as indicated by the gray background of button 1518 inFIG. 15A. As such, autonomous vehicle display 1520 shows high-leveldata, represented as graphical objects, representing autonomous vehicleAV×123 1530, road 1532, gates 1534 a, 1534 b, bovines 1542, 1544, andcalves 1546 and 1548. In scenario 1500, bovines 1542, 1544 and calves1546, 1548 are travelling to the left, crossing road 1532 to enter afield (not shown) accessible via an opening between gate 1534 a and gate1534 b. Autonomous vehicle AV×123 1530 has an original trajectory 1540that would impact bovine 1542 at or shortly after time “17:23:04 PDT”.

As such, autonomous vehicle AV×123 1530 is in a stuck condition. Inscenario 1500, prior to requesting assistance, autonomous vehicle AV×1231530 may have waited for a timer to expire upon determining this stuckcondition, such as discussed in detail in the context of FIG. 7, basedon a cause that bovines 1542, 1544 and calves 1546, 1548 are obstructingtrajectory 1540. At 17:23:04 PDT, as shown in FIG. 15A, only bovine 1542remains obstructing trajectory 1540.

Display controls section 1570 of trajectory UI 1510 is shown in FIG. 15Awith six buttons: show autonomous vehicle trajectory button 1580, showattractors button 1582, show repellers button 1584, draw new trajectorybutton 1586, send new trajectory button 1588, and approve trajectorybutton 1590. FIG. 15A shows that buttons 1580 and 1584 are selected andbuttons 1582, 1586, 1588, and 1590 are not selected. In someembodiments, more, less, or different buttons are provided in thedisplay controls section of trajectory UI 1510.

Autonomous vehicle trajectory button 1580, when selected, instructsautonomous vehicle display 1520 to display a trajectory for the selectedautonomous vehicle. As autonomous vehicle trajectory button 1580 isselected, trajectory 1540 for selected autonomous vehicle AV×123 isdisplayed on display 1520. FIG. 15A shows trajectory 1540 as an arrowfrom a display of high-level object 1530 representing AV×123 goingtoward the top of the figure. In some embodiments, if autonomous vehicletrajectory button 1580 were selected again, autonomous vehicletrajectory button 1580 may act as a toggle and display 1520 would nolonger display trajectory 1540.

Show attractors button 1582 may, when selected, instruct autonomousvehicle display 1520 to show “attractors.” Similarly, show repellersbutton 1584 may, when selected, instruct autonomous vehicle display 1520to show “repellers.” In some embodiments, providing trajectories to anautonomous vehicle may be modeled as an energy minimization problemdefined by a series of attractors and repellers. These attractors andrepellers may be placed by an expert, or may be automatically determinedby autonomous vehicle AV×123.

One or more attractors, or positive potentials, may exist or may beinserted along a center of a lane of road 1532. Attractors may be placedin other positions that are desirable for autonomous vehicle travel.Attractors are not explicitly shown in FIGS. 15A, 15B, and 15C.

Repellers, or negative potentials, may exist or may be inserted atundesirable positions, such at the edges of lanes and surroundingobstacles that may partially or completely block a trajectory of anautonomous vehicle. In FIGS. 15A-15C, repellers are shown in autonomousvehicle display 1520 as dashed lines. For instance, repellers 1542 r,1544 r, 1546 r, 1548 r exist around bovines/calves 1542, 1544, 1546,1548, respectively. Repellers are also shown near the edges of road1532.

In some embodiments, an expert may specify an endpoint and a series ofattractors and repellers with controls for varying the strength andradius of effect of these potentials. These data may be provided toautonomous vehicle AV×123 to define a new trajectory that tries to takeattractive paths and avoid repelled paths.

Draw new trajectory button 1586, when selected, allows the expert toenter an augmented trajectory for autonomous vehicle AV×123. Send newtrajectory button 1588, when selected, allows the expert to send theaugmented trajectory for autonomous vehicle AV×123. Approve trajectorybutton 1590, when selected, allows the expert to send a message to theautonomous vehicle that approves a trajectory sent by autonomous vehicleAV×123. Once a trajectory is approved, autonomous vehicle AV×123 maydrive along the approved trajectory to relieve a stuck condition, or foranother purpose.

In some embodiments, an augmented or new trajectory for an autonomousvehicle may be specified based on two points: a point of departure froman existing trajectory and an endpoint. The endpoint may be a point ofreturn to the existing trajectory or a point that is not part of theexisting trajectory. For instance, the endpoint might specify a locationto which the autonomous vehicle can drive that at least partiallyrelieves the stuck condition. In particular embodiments, the point ofdeparture may be inferred as a current position of the autonomousvehicle, and so only the point of return may be explicitly specified.

The trajectory may also include collection of waypoints to navigatebetween (i) the point of departure or a current position, and (ii) theendpoint of the trajectory. The collection of waypoints may be specifiedusing a spline, which is a piecewise-smooth function connected by thewaypoints. Upon reaching the endpoint, the autonomous vehicle maycontinue with the original trajectory. In some embodiments, some or allof the collection of waypoints may be specified other than by a spline;e.g., using piecewise linear functions, other piecewise-smoothfunctions, polynomials, lists of waypoints, etc.

Turning to FIG. 15B, scenario 1500 continues at time “17:23:49 PDT”where autonomous vehicle AV×123 has provided a proposed trajectory 1550and proposed maximum speed 1552 to relieve the stuck condition. FIG. 15Bshows that autonomous vehicle display 1520 portrays proposed trajectory1550 as a relatively thin arrow from a starting point or point ofdeparture, shown as the letter “s” in a circle, through a waypoint shownas the letter “A” in a circle, to an endpoint or point of return, shownas the letter “e” in a circle. In some embodiments, an autonomousvehicle may propose a maximum speed to travel on a proposed trajectory.FIG. 15B shows the proposed maximum speed 1552 for trajectory 1550 of1.2 meters/second. In some embodiments, an autonomous vehicle maypropose a trajectory to relieve a stuck condition (or for some otherpurpose) without proposing a related speed, such as a maximum, minimumor average speed. Alternatively or additionally, the autonomous vehiclemay also or instead propose minimum and/or average speeds.

Upon reviewing proposed trajectory 1550, the expert may determine thatproposed trajectory 1550 may come too close to bovine 1542. Then, theexpert may specify a different trajectory than proposed trajectory 1550.In scenario 1500, as shown in FIG. 15B, the expert may press draw newtrajectory button 1586 to specify a trajectory.

FIG. 15C shows that scenario 1500 continues at time “17:24:04 PDT” withdraw new trajectory button 1586 selected. The expert has also specifiednew trajectory 1560 connecting the point of departure “s” and the pointof return “e” of proposed trajectory 1550 using spline 1564 with threewaypoints. The new trajectory 1560 takes a wider path around bovine1542, and should be safer for autonomous vehicle AV×123 than proposedtrajectory 1550. In scenario 1500, a maximum speed for traveling alongtrajectory 1560 may be specified by dialog 1562, which shows a currentmaximum speed selection of 1.2 meters per second, a “+” button forincrementing the maximum speed, and an “−” for decrementing the maximumspeed.

FIG. 15C shows spline 1564 using a dotted and dashed line connectingpoints “s” and “e” and the three waypoints using circled numbers “1”,“2”, and “3”. In some embodiments, different techniques may be used todisplay trajectories proposed by autonomous vehicles and/or by experts;e.g., different colors, fonts, characters, etc. may be used todistinguish trajectories.

Feedback may be used to aid an expert in drawing a trajectory. Forexample, if show repellers button 1584 is selected, as shown in FIG.15C, then trajectory interface 1510 may generate a vibration, sound, orgraphical indication when a drawn trajectory touches a repeller or anobject. As another example, if show attractors button 1582 is selected,trajectories may be pre-selected by trajectory interface 1510 thatpartially or completely follow one or more attractors that areunobstructed by objects. Other examples are possible as well.

While not shown in the figures, scenario 1500 may continue with theexpert pressing send new trajectory button 1588. Pressing send newtrajectory button 1588 may instruct trajectory interface 1510 to sendtrajectory 1560 to autonomous vehicle AV×123. Autonomous vehicle AV×123may then examine trajectory 1560 and request approval of the trajectory.Upon receiving the request, trajectory interface 1510 may provide anindication of the request for approval. Then, the expert may press theapprove trajectory 1590 button to send an approval to autonomous vehicleAV×123. Autonomous vehicle AV×123 may then drive along trajectory 1560from point of departure “s” via waypoints “1”, “2”, and “3” to reachpoint of return “e”. Upon reaching point “e”, the stuck condition forautonomous vehicle AV×123 is relieved and scenario 1500 may end.

FIG. 16 shows a block diagram of components of an example autonomousvehicle 1600. In some embodiments, autonomous vehicle 1600 may includeat least some of the herein-described functionality of autonomousvehicles 510, 512, 514, 610, 810, 1010, and 1800. Additionally,autonomous vehicle 1600 may be configured to operate in an operationalmode, such as a non-autonomous mode, a partially-autonomous mode, or anautonomous-operation mode.

The non-autonomous mode may use human input to select and executedriving behaviors during operation of the autonomous vehicle. In someinstances, while in non-autonomous mode, the autonomous vehicle mayoperate like a traditional, non-autonomous vehicle.

The partially-autonomous mode may involve both a vehicle control system,such as control system 1606 of autonomous vehicle 1600, and human inputsto select driving behaviors during operation of autonomous vehicle 1600.For example, the autonomous vehicle control system may generateindications of driving behaviors for review by a human driver. For eachindication, the human driver may review the indication and operate theautonomous vehicle by carrying out, modifying, or ignoring theindication. In some cases, the partially-autonomous mode may involve theautonomous vehicle performing all actions to navigate and drive theautonomous vehicle, where a human driver may monitor the autonomousvehicle's performance and intervene if and when necessary; e.g., toavert an accident. In other cases, as described herein, autonomousvehicle 1600 may request assistance from an assistance center; e.g.,assistance center 520. Additional techniques for operating an autonomousvehicle in a partially-autonomous mode, such as auto-piloting andautomatic parking, are possible as well.

In the autonomous-operation mode, the autonomous vehicle control systemmay select and execute driving behaviors along at least part of a routewithout human input. The autonomous-operation mode may be subdividedinto an autonomous mode utilizing a trained driver, an autonomous modewith a non-trained human driver, and an autonomous mode without a humandriver. In autonomous-mode operation with a human driver, the vehiclecontrol 1606 system may be configured to receive feedback from the humanpassenger about driving quality of the autonomous vehicle, and, in somecircumstances, for the human driver to operate the autonomous vehicle.

Autonomous vehicle 1600 may include various systems such as a propulsionsystem 1602, a sensor system 1604, a control system 1606, one or moreperipherals 1608, as well as a power supply 1670, a computing device1680, and a user interface 1690. Autonomous vehicle 1600 may includemore or fewer systems and each system may include multiple aspects.Further, each of the systems and aspects of autonomous vehicle 1600 maybe interconnected. Thus, one or more of the described functions ofautonomous vehicle 1600 may be divided into additional functional orphysical components, or combined into fewer functional or physicalcomponents. In some further examples, additional functional and/orphysical components may be added to the examples illustrated by FIG. 16.

Propulsion system 1602 may include components operable to providepowered motion for autonomous vehicle 1600. In an example embodiment,propulsion system 1602 may include an engine/motor 1610, an energysource 1612, a transmission 1614, and wheels/tires 1616. Engine/motor1610 may be any combination of an internal combustion engine, anelectric motor, steam engine, Stirling engine, or other types of enginesand/or motors. In some embodiments, engine/motor 1610 may be configuredto convert energy source 1612 into mechanical energy. Propulsion system1602 may include multiple types of engines and/or motors. For instance,a gas-electric hybrid car may include a gasoline engine and an electricmotor. Other examples are possible.

Energy source 1612 may represent a source of energy that may, in full orin part, power engine/motor 1610. That is, engine/motor 1610 may beconfigured to convert energy source 1612 into mechanical energy.Examples of energy sources 1612 include gasoline, diesel, otherpetroleum-based fuels, propane, other compressed gas-based fuels,ethanol, solar panels, batteries, and other sources of electrical power.Energy source 1612 may additionally or alternatively include anycombination of fuel tanks, batteries, capacitors, and/or flywheels.Energy source 1612 may also provide energy for other systems ofautonomous vehicle 1600.

Transmission 1614 may include aspects that are operable to transmitmechanical power from engine/motor 1610 to wheels/tires 1616. To thisend, transmission 1614 may include a gearbox, clutch, differential, anddrive shafts. Transmission 1614 may include other aspects. The driveshafts may include one or more axles that may be coupled to the one ormore wheels/tires 1616.

Wheels/tires 1616 of autonomous vehicle 1600 may be configured invarious formats, including a unicycle, bicycle/motorcycle, tricycle, orcar/truck four-wheel format. Other wheel/tire geometries are possible,such as those including six or more wheels. Any combination ofwheels/tires 1616 of autonomous vehicle 1600 may be operable to rotatedifferentially with respect to other wheels/tires 1616. Wheels/tires1616 may represent at least one wheel that is fixedly attached totransmission 1614 and at least one tire coupled to a rim of the wheelthat may make contact with the driving surface. Wheels/tires 1616 mayinclude any combination of metal and rubber, or another combination ofmaterials.

Sensor system 1604 may include a number of sensors configured to senseinformation about an environment of autonomous vehicle 1600. Forexample, sensor system 1604 may include a GPS 1620, an inertialmeasurement unit (IMU) 1622, a radar unit 1624, a LIDAR unit 1626, and acamera 1628. Other sensors are possible as well. One or more of thesensors included in sensor system 1604 may be configured to be actuatedseparately and/or collectively in order to modify a position and/or anorientation of the one or more sensors.

GPS 1620 may be any sensor configured to estimate a geographic locationof autonomous vehicle 1600. To this end, GPS 1620 may include atransceiver operable to provide information regarding the position ofautonomous vehicle 1600 with respect to the Earth.

IMU 1622 may include any combination of sensors (e.g., accelerometersand gyroscopes) configured to sense position and orientation changes ofautonomous vehicle 1600 based on inertial acceleration.

Radar unit 1624 may represent a system that utilizes radio signals tosense objects within the local environment of autonomous vehicle 1600.In some embodiments, in addition to sensing the objects, radar unit 1624may additionally be configured to sense the speed and/or heading of theobjects.

LIDAR unit 1626 may be any sensor configured to sense objects in theenvironment in which autonomous vehicle 1600 is located using lasers. Inan example embodiment, LIDAR unit 1626 may include one or more lasersources, a laser scanner, and one or more detectors, among other systemcomponents. LIDAR unit 1626 may be configured to operate in a coherent(e.g., using heterodyne detection) or an incoherent detection mode. Insome embodiments, LIDAR unit 1626 may include at least some of theherein-described functionality of LIDAR unit 1102.

Camera 1628 may include one or more devices configured to capture aplurality of images of the environment of autonomous vehicle 1600.Camera 1628 may be a still camera or a video camera, and may capable ofrecording images in the infrared, visible, and/or ultraviolet frequencyranges. Camera 1628 may operate in conjunction with light source 1668.

In some embodiments, obstacle data 1630 be stored as part of sensorsystem 1604. Obstacle data 1630 may include image data 1632 and sensordata 1634. Image data 1632 may include still and/or video imagescaptured by autonomous vehicle 1600; e.g., using camera 1628. Sensordata may include location, radar, LIDAR, laser strike data, audio data,and/or other data captured by autonomous vehicle 1600; e.g., using GPS1620, IMU 1622, radar unit 1624, LIDAR unit 1626, microphone 1664,and/or data generated by sensors within other components of autonomousvehicle 1600, such as but not limited to engine, brake, and tiresensors.

In some embodiments, sensor data 1634 may include low-level data, or rawdata from sensors associated with autonomous vehicle 1600; e.g., radardata from radar unit 1624, laser-strike data from LIDAR unit 1626,and/or locations from GPS 1620 and IMU 1622. Alternatively oradditionally, sensor data 1634 may include high-level data, or processeddata from sensors associated with autonomous vehicle 1600. Thishigh-level data may be derived, as least in part, from the low-leveldata.

In still other embodiments, sensor data 1634 may include both low-leveland high-level data. In even other embodiments, part of all ofobstacle/object data 1630 may be stored using computing device 1680,either as a copy of data stored in sensor system 1604, or rather thanbeing stored in sensor system 1604.

In some embodiments, data storage associated with computer device 1680may store object-detector software, code, or other program instructions.Such object-detector software may include, or be part of, one or more ofthe subsystems of the control system 1606 described below, includingsensor fusion algorithm 1650, computer vision system 1652, and/orobstacle avoidance system 1656.

In some embodiments, the low level data and/or the high level data maybe grouped or “bucketed” according to distance along a proposedtrajectory of autonomous vehicle 1600. For example, suppose buckets ofsize R meters, R>0, are used. Then, data between X and X+R meters aheadof autonomous vehicle 1600 may be put into bucket X. In someembodiments, X is divisible by R. If bucket X includes more than athreshold number T_(obj) of data objects, the proposed trajectory may beconsidered to intersect or come close to an obstacle somewhere between Xmeters and X+R meters ahead.

Buckets may be used to test a proposed trajectory for safety. Forexample, if a bucket along the proposed trajectory has more than T_(obj)objects, then the proposed trajectory may be rejected by autonomousvehicle 1600. Similarly, if autonomous vehicle 1600 is driving along atrajectory and determines that a bucket between X1 meters ahead has morethan T_(obj) objects, then autonomous vehicle 1600 may come tocontrolled stop to avoid a collision approximately X1 meters away.Alternatively, if there is just one object blocking a trajectory,autonomous vehicle 1600 may reject the trajectory.

Control system 1606 may be configured to control operation of autonomousvehicle 1600 and its components. Accordingly, the control system 1606may include various aspects include stuck condition detector 1640,trajectory validation unit 1642, driving/steering unit 1644, throttle1646, brake unit 1648, a sensor fusion algorithm 1650, a computer visionsystem 1652, a navigation/pathing system 1654, and an obstacle avoidancesystem 1656. Control system 1606 may additionally or alternativelyinclude components other than those shown and described.

Stuck condition detector 1640 may be configured to detect that theautonomous vehicle is in a stuck condition, so that autonomous vehicle1600 may benefit from navigational assistance. In some embodiments,stuck condition detector 1640 may be a component of navigation-pathingsystem 1654. In other embodiments, stuck condition detector 1640 may bea component of obstacle avoidance system 1656.

Upon determining that autonomous vehicle 1600 is in a stuck condition,stuck condition detector 1640 may, in combination with communicationscomponent 1660, send an assistance request to request assistance. Theassistance request may be sent to assistance center 520. In response,assistance center 520 may either (a) accept the assistance request andsend a new trajectory for vehicle 1600 to navigate, or (b) reject therequest. In some embodiments, autonomous vehicle 1600 may provide aproposed new trajectory to assistance center 520, either for validation,editing, or replacement by a trajectory proposed by assistance center520. In some embodiments, the functions of assistance center 520 may beintegrated with autonomous vehicle 1600, perhaps as a way for a humandriver or rider of autonomous vehicle 1600 to assist autonomous vehicle1600 out of a stuck condition.

Trajectory validation component 1642 may determine whether or notautonomous vehicle 1600 may follow a new trajectory proposed byassistance center 520. Trajectory validation component 1642 may validatethe trajectory using data from sensors, such as indicated in sensorsystem 1604, and navigational constraints on autonomous vehicle 1600. Insome embodiments, trajectory validation component 1642 may use bucketsfor validation as discussed elsewhere in this section. In otherembodiments, assistance center 520 may provide temporary permission toautonomous vehicle 1600 to ignore some navigational constraints.

Driving/steering unit 1644 may include a steering unit representing anycombination of mechanisms that may be operable to adjust the heading ofautonomous vehicle 1600 and a driving unit. Driving/steering unit 1644may be configured to drive in accordance with a trajectory, such as theoriginal trajectory, and to accept modifications to the originaltrajectory and/or constraints based on a new trajectory, as well as anyother information provided by assistance center 520. The new trajectorymay be based on a point of departure, a path that may be specified as aspline, and a point of return to an original trajectory, such asdiscussed above at least in the context of FIGS. 15A-15C.

Throttle 1646 may be configured to control, for instance, the operatingspeed of the engine/motor 1610 and, in turn, control the speed ofautonomous vehicle 1600.

Brake unit 1648 may include any combination of mechanisms configured todecelerate autonomous vehicle 1600. Brake unit 1648 may use friction toslow wheels/tires 1616. In some cases, brake unit 1648 may convert thekinetic energy of wheels/tires 1616 to electric current. Brake unit 1648may take other forms as well.

Sensor fusion algorithm 1650 may be an algorithm (or a computer programproduct storing an algorithm) configured to accept data from sensorsystem 1604 as input. The data may include, for example, datarepresenting information sensed at the sensors of sensor system 1604.Sensor fusion algorithm 1650 may include, for instance, a Kalman filter,Bayesian network, or other algorithm. Sensor fusion algorithm 1650 mayfurther provide various assessments based on the data from sensor system1604. In an example embodiment, the assessments may include evaluationsof individual objects and/or features in the environment of autonomousvehicle 1600, evaluation of a particular situation, and/or evaluatepossible impacts based on the particular situation. Sensor fusionalgorithm 1650 may operate in conjunction with stuck condition detector1640, trajectory validation system 1642, and/or other components ofautonomous vehicle 1600.

Computer vision system 1652 may be any system operable to process andanalyze images captured by camera 1630 in order to identify objectsand/or features in the environment of autonomous vehicle 1600 that mayinclude traffic signals, road way boundaries, and obstacles. Computervision system 1652 may use an object recognition algorithm, a Structurefrom Motion (SFM) algorithm, video tracking, and other computer visiontechniques. In some embodiments, computer vision system 1652 may beadditionally configured to map an environment, track objects, estimatethe speed of objects, etc. Computer vision system 1652 may operate inconjunction with stuck condition detector 1640, trajectory validationsystem 1642, and/or other components of autonomous vehicle 1600.

Navigation and pathing system 1654 may be any system configured todetermine a driving path for autonomous vehicle 1600. Navigation andpathing system 1654 may additionally be configured to update the drivingpath dynamically while autonomous vehicle 1600 is in operation. In someembodiments, navigation and pathing system 1654 may be configured toincorporate data from sensor fusion algorithm 1650, GPS 1620, and one ormore predetermined maps so as to determine a trajectory for autonomousvehicle 1600.

Obstacle avoidance system 1656 may represent a control system configuredto identify, evaluate, and avoid or otherwise negotiate potentialobstacles in the environment of autonomous vehicle 1600. Peripherals1608 may be configured to allow interaction between autonomous vehicle1600 and external sensors, other vehicles, other computer systems,and/or a user. For example, peripherals 1608 may include a communicationsystem (comms) 1660, a touchscreen 1662, a microphone 1664, a speaker1666, and/or a light source 1668.

Peripherals 1608 may provide, for instance, an interface for a user ofautonomous vehicle 1600 to interact with autonomous vehicle 1600. Tothis end, touchscreen 1662 may provide information to a user ofautonomous vehicle 1600. Touchscreen 1662 may also be configured tosense at least one of a position and a movement of a user's finger viacapacitive sensing, resistance sensing, or a surface acoustic waveprocess, among other possibilities. Touchscreen 1662 may be capable ofsensing finger movement in a direction parallel or planar to thetouchscreen surface, in a direction normal to the touchscreen surface,or both, and may also be capable of sensing a level of pressure appliedto the touchscreen surface. Touchscreen 1662 may be formed of one ormore translucent or transparent insulating layers and one or moretranslucent or transparent conducting layers. Touchscreen 1662 may takeother forms as well.

Peripherals 1608 may also provide facilitate communication betweenautonomous vehicle 1600 and devices within its environment. Themicrophone 1664 may be configured to receive audio (e.g., a voicecommand or other audio input) from a user of autonomous vehicle 1600.Similarly, speakers 1666 may be configured to output audio to theautonomous user of autonomous vehicle 1600.

Communication system 1660 may be a wireless communication systemconfigured to wirelessly communicate with one or more devices directlyor via a communication network. For example, communication system 1660may use 3G cellular communication, such as Code-Division Multiple Access(CDMA), Evolution Data-Only (EVDO), or Universal MobileTelecommunications System (UMTS), and/or 4G cellular communication, suchas Worldwide Interoperability for Microwave Access (WiMAX) or Long TermEvolution (LTE). Alternatively, communication system 1660 may use aWLAN, for example, using WiFi. In some embodiments, communication system1660 may communicate directly with a device, for example, using aninfrared link, Bluetooth, or ZigBee. Other wireless protocols, such asvarious vehicular communication systems, are possible within the contextof the disclosure. For example, communication system 1660 may includeone or more dedicated short range communications (DSRC) devices that mayinclude public and/or private data communications between vehiclesand/or roadside stations. In some embodiments, communication system 1660may be configured to communicate using wired communication.

Light source 1668 may generate and provide light to illuminate theenvironment of autonomous vehicle 1600, and may include, but is notlimited to, one or more headlights, taillights, indicators, fog lights,light bulbs, halogen lights, light emitting diodes (LEDs), turn signals,beams, and lighting assemblies.

Power supply 1670 may provide power to various components of autonomousvehicle 1600 and may represent, for example, a rechargeable lithium-ionor lead-acid battery. In some embodiments, one or more banks of suchbatteries may be configured to provide electrical power. Other powersupply materials and configurations are possible. In some embodiments,power supply 1670 and energy source 1612 may be implemented together, asin some all-electric cars.

Many or all of the functions of vehicle 1600 may be controlled by acomputing device 1680. In some embodiments, computing device 1680 mayinclude multiple computing devices. For example, computing device 1680may control the function of autonomous vehicle 1600 based on inputsreceived from various systems (e.g., propulsion system 1602, sensorsystem 1604, and control system 1606), as well as from peripherals 1608.For example, computing device 1680 may utilize input from control system1606 in order to control driving/steering unit 1654 to avoid an obstacledetected by sensor system 1604 and obstacle avoidance system 1656.

In an example embodiment, computing device 1680 may control many aspectsof autonomous vehicle 1600 and its systems. In another exampleembodiment, computing device 1680 may be configured to carry out part orall of the herein-described methods; e.g., methods 100, 200, 300, 400,700, and 1000 and/or perform some or all the autonomous vehiclefunctionality described herein. In some embodiments, computing device1680 may be configured to store some or all of obstacle/object data1630, video data 1632, and sensor data 1634.

Although FIG. 16 shows various components of autonomous vehicle 1600,such as communication system 1660 and computing device 1680, as beingintegrated into autonomous vehicle 1600, one or more of these componentsmay be mounted or associated separately from autonomous vehicle 1600.For example, computing device 1680 may, in part or in full, existseparate from autonomous vehicle 1600. The device aspects that make upautonomous vehicle 1600 may be communicatively coupled together in awired and/or wireless fashion.

Within the context of the present disclosure, the components ofautonomous vehicle 1600 may be configured to work in an interconnectedfashion with other components within or outside their respectivesystems. For instance, the camera 1628 may capture a plurality of imagesthat may represent sensor data relating to an environment of autonomousvehicle 1600 operating in an autonomous mode. The environment mayinclude another vehicle blocking a known traffic signal location aheadof autonomous vehicle 1600. Based on the plurality of images, aninference system (which may include computing device 1680, sensor system1604, and control system 1606) may infer that the unobservable trafficsignal is red based on sensor data from other aspects of the environment(for instance images indicating the blocking vehicle's brake lights areon). Based on the inference, computing device 1680 and propulsion system1602 may act to control autonomous vehicle 1600.

FIG. 17 shows a block diagram of components of an example assistancecenter 520. Assistance center 520 may be configured with trajectorycomponent 1702, autonomous vehicle data component 1704, storagecomponent 1706, and peripheral component 1708. In some embodiments,assistance center 520 may have more, different, or fewer components thanshown in FIG. 17.

Trajectory component 1702 may include trajectory expert 1710, trajectoryspecification component 1712, and trajectory validation component 1714.Trajectory expert 1710 may be configured to receive data from anautonomous vehicle in a stuck condition and determine a new trajectoryfor the autonomous vehicle to relieve the stuck condition. Trajectoryexpert 1710 may include a human expert, an expert system and/or othercomputer components configured for determining new trajectories, and/ora combination of human expert(s) and computer component(s). Trajectoryspecification component 1712 may be configured to enable trajectoryexpert 1710 to specify trajectories; e.g., receive a curve or points asinput and generate a new trajectory as discussed above.

In some embodiments, an autonomous vehicle, such as autonomous vehicle1600, may propose new trajectories to relieve stuck conditions. In theseembodiments, trajectory validation component 1714 may be used to verifywhether a trajectory provided by an autonomous vehicle may relieve astuck condition. In particular embodiments, trajectory validationcomponent 1714 may be used to validate trajectories from other sources,such as another assistance center or a stored set of trajectory oftrajectories 1732 to determine whether the other-sourced trajectory mayrelieve the stuck condition.

Autonomous vehicle data components 1704 include signal receiver 1720,autonomous vehicle data receiver 1722, and assistance response 1724.Signal receiver 1720 may receive assistance signals, such as “heartbeat”signals and other signals from one or more autonomous vehicles. In someembodiments, signal receiver 1720 may be configured to receive periodicheartbeat signals from an autonomous vehicle informing assistance center520 about a status of the autonomous vehicle. In some embodiments,assistance signals may be carried as part of heartbeat signals.Autonomous vehicle data receiver 1722 may receive data, such as but notlimited to, sensor data, video data, audio data, object/obstacleinformation, and location data, from autonomous vehicle(s) contactingassistance center 520. Signal receiver 1720 and autonomous vehicle datareceiver 1722 may be configured to store respective signals and data instorage components 1706.

Storage components may include representations of stored signals anddata 1730 and trajectories 1732. Stored signals and data 1730 andtrajectories 1732 may be configured so that trajectory expert 1710, oranother component of assistance center 520, or even another assistancecenter, may query storage components 1706 to search for trajectoriesbased on various criteria. These criteria may include, but are notlimited to, a physical location, similarity to another trajectory,and/or how recently the stored trajectory was used. One or moretrajectories found by such a search may be considered for use by anautonomous vehicle.

Peripheral components 1708 include communications components 1740 forcommunicating at least with autonomous vehicles as described herein, agraphical user interface (GUI) 1742 for displaying output displays(perhaps with a touch screen for receiving touch-based input), andtrajectory user interface 1744 for use, e.g., by trajectory expert 1710,for specifying trajectories to trajectory specification component 1712and/or trajectory validation component 1714. Other peripherals, such askeyboard(s), speaker(s), computer mice, additional displays, and/orprinters, may be components of assistance center 520. In someembodiments, GUI 1742 may include or be replaced by a text orcommand-based user interface. GUI 1742 may display the screens shown inFIGS. 15A, 15B, and 15C, and may also support the function described inthe context of these figures.

FIG. 18 depicts an autonomous vehicle 1800 that may be capable ofcarrying out one or more of the functions, methods, and/or processesdescribed herein. For instance, autonomous vehicle 1800 may be similaror identical to autonomous vehicle 1600. Although autonomous vehicle1800 is illustrated in FIG. 18 as a car, other embodiments are possible.For instance, autonomous vehicle 1800 may represent a truck, a van, asemi-trailer truck, a motorcycle, a golf cart, an off-road vehicle, or afarm vehicle, among other examples.

In some embodiments, autonomous vehicle 1800 may include a sensor unit1802, a wireless communication system 1804, a LIDAR unit 1806, a laserrangefinder unit 1808, a camera 1810, and light sources 1812 a, 1812 b,1812 c, 1812 d. The aspects of autonomous vehicle 1800 may include someor all of the aspects described for FIG. 16.

The sensor unit 1802 may include one or more different sensorsconfigured to capture information about an environment of autonomousvehicle 1800. For example, sensor unit 1802 may include any combinationof camera units, radar units, LIDAR units, range finders, and acousticsensors. Other types of sensors are possible.

In an example embodiment, the sensor unit 1802 may include one or moremovable mounts that may be operable to adjust the orientation of one ormore sensors in the sensor unit 1802. In one embodiment, the movablemount may include a rotating platform that may scan sensors so as toobtain information from each direction around autonomous vehicle 1800.In another embodiment, the movable mount of the sensor unit 1802 may bemovable in a scanning fashion within a particular range of angles and/orazimuths. The sensor unit 1802 may be mounted atop the roof of a car,for instance, however other mounting locations are possible.Additionally, the sensors of sensor unit 1802 may be distributed indifferent locations and might not be collocated in a single location.Some possible sensor types and mounting locations include LIDAR unit1806 and laser rangefinder unit 1808. Furthermore, each sensor of sensorunit 1802 may be configured to be moved or scanned independently ofother sensors of sensor unit 1802.

Wireless communication system 1804 may be located on a roof ofautonomous vehicle 1800 as depicted in FIG. 18. Alternatively, wirelesscommunication system 1804 may be located, fully or in part, elsewhere.Wireless communication system 1804 may include wireless transmitters andreceivers that may be configured to communicate with devices external orinternal to autonomous vehicle 1800. Specifically, wirelesscommunication system 1804 may include transceivers configured tocommunicate with other vehicles and/or computing devices, for instance,in a vehicular communication system or a roadway station. Examples ofsuch vehicular communication systems include wide-area wirelesscommunication system (such as 3G and/or 4G cellular systems), WLANsystems, GPS systems, dedicated short range communications (DSRC), radiofrequency identification (RFID), and other proposed communicationstandards directed towards intelligent transport systems.

Camera 1810 may be any camera (e.g., a still camera, a video camera,etc.) configured to capture a plurality of images of the environment ofautonomous vehicle 1800. To this end, camera 1810 may be configured todetect visible light, or may be configured to detect light from otherportions of the spectrum, such as infrared or ultraviolet light. Othertypes of cameras are possible as well.

Camera 1810 may be a two-dimensional detector, or may have athree-dimensional spatial range. In some embodiments, camera 1810 maybe, for example, a range detector configured to generate atwo-dimensional image indicating a distance from camera 1810 to a numberof points in the environment. To this end, camera 1810 may use one ormore range detecting techniques. For example, camera 1810 may use astructured light technique in which autonomous vehicle 1800 illuminatesan object in the environment with a predetermined light pattern, such asa grid or checkerboard pattern and uses camera 1810 to detect areflection of the predetermined light pattern off the object. Based ondistortions in the reflected light pattern, autonomous vehicle 1800 maydetermine the distance to the points on the object. The predeterminedlight pattern may include infrared light, or light of anotherwavelength.

Camera 1810 may be mounted inside a front windshield of autonomousvehicle 1800. Specifically, as illustrated, camera 1810 may captureimages from a forward-looking view with respect to autonomous vehicle1800. Other mounting locations and viewing angles of camera 1810 arepossible, either inside or outside autonomous vehicle 1800.

Camera 1810 may have associated optics that may be operable to providean adjustable field of view. Further, camera 1810 may be mounted toautonomous vehicle 1800 with a movable mount that may be operable tovary a pointing angle of camera 1810. Camera 1810 may operate inconjunction with one or more of light sources 1812 a, 1812 b, 1812 c,1812 d.

Each of light sources 1812 a, 1812 b, 1812 c, 1812 d may be a lightsource such as light source 1668 discussed above in the context of FIG.16. For example, each of light sources 1812 a, 1812 b may be a headlight. Each head light may be configured to generate and provide whiteor nearly white light and project the (nearly) white light in front ofautonomous vehicle 1800. As another example, each of light sources 1812c, 1812 d is a tail light. Each tail light may be configured to generateand provide yellow, red, and/or white light behind autonomous vehicle1800. Other example light sources are possible as well, including butnot limited to, additional light sources, light sources configured toprovide different and/or additional colors of light, and light sourcesmounted in locations on autonomous vehicle 1800 other than shown in FIG.18.

FIG. 19A is a block diagram of computing device 1900, in accordance withan example embodiment. Computing device 1900 shown in FIG. 19A could beconfigured to perform one or more functions of computing device 1680,some or all of methods 100, 200, 300, 400, 700, and 1000, control someor all of the functionality of autonomous vehicles 510, 512, 514, 610,810, 1010, 1110, 1600, and 1800, and/or some or all of the functionalityof assistance center 520. Computing device 1900 may include a userinterface module 1901, a network-communication interface module 1902,one or more processors 1903, and data storage 1904, all of which may belinked together via a system bus, network, or other connection mechanism1905.

User interface module 1901 may be operable to send data to and/orreceive data from external user input/output devices. For example, userinterface module 1901 may be configured to send and/or receive data toand/or from user input devices such as a keyboard, a keypad, a touchscreen, a computer mouse, a track ball, a joystick, a camera, a voicerecognition module, and/or other similar devices. User interface module1901 may also be configured to provide output to user display devices,such as one or more cathode ray tubes (CRT), liquid crystal displays(LCD), light emitting diodes (LEDs), displays using digital lightprocessing (DLP) technology, printers, light bulbs, and/or other similardevices, either now known or later developed. User interface module 1901may also be configured to generate audible output(s), such as a speaker,speaker jack, audio output port, audio output device, earphones, and/orother similar devices.

Network-communications interface module 1902 may include one or morewireless interfaces 1907 and/or one or more wireline interfaces 1908that are configurable to communicate via a network. Wireless interfaces1907 may include one or more wireless transmitters, receivers, and/ortransceivers, such as a Bluetooth transceiver, a Zigbee transceiver, aWLAN transceiver, a WWAN transceiver, and/or other similar type ofwireless transceiver configurable to communicate via a wireless network.Wireline interfaces 1908 may include one or more wireline transmitters,receivers, and/or transceivers, such as an Ethernet transceiver, aUniversal Serial Bus (USB) transceiver, or similar transceiverconfigurable to communicate via a twisted pair wire, a coaxial cable, afiber-optic link, or a similar physical connection to a wirelinenetwork.

In some embodiments, network communications interface module 1902 may beconfigured to provide reliable, secured, and/or authenticatedcommunications. For each communication described herein, information forensuring reliable communications (i.e., guaranteed message delivery) maybe provided, perhaps as part of a message header and/or footer (e.g.,packet/message sequencing information, encapsulation header(s) and/orfooter(s), size/time information, and transmission verificationinformation such as cyclic redundancy check (CRC) and/or parity checkvalues). Communications may be made secure (e.g., be encoded orencrypted) and/or decrypted/decoded using one or more cryptographicprotocols and/or algorithms, such as, but not limited to, the DataEncryption Standard (DES), the Advanced Encryption Standard (AES),Rivest-Shamir-Adleman (RSA), Diffie-Hellman, and/or other techniques.Thus, various cryptographic protocols and/or algorithms may be used tosecure (and then decrypt/decode) communications.

Processors 1903 may include one or more general purpose processorsand/or one or more special purpose processors (e.g., digital signalprocessors, application specific integrated circuits, etc.). Processors1903 may be configured to execute computer-readable program instructions1906 that are contained in data storage 1904 and/or other instructionsas described herein.

Data storage 1904 may include one or more computer-readable storagemedia that may be read and/or accessed by at least one of processors1903. The one or more computer-readable storage media may includevolatile and/or non-volatile storage components, such as optical,magnetic, organic or other memory or disc storage, which may beintegrated in whole or in part with at least one of processors 1903. Insome embodiments, data storage 1904 may be implemented using a singlephysical device (e.g., one optical, magnetic, organic or other memory ordisc storage unit), while in other embodiments, data storage 1904 may beimplemented using two or more physical devices.

Data storage 1904 may include computer-readable program instructions1906, and perhaps additional data. In some embodiments, data storage1904 may additionally include storage used to perform at least part ofthe herein-described methods and techniques and/or at least part of thefunctionality of the herein-described devices and networks.

FIG. 19B depicts a network 1914 of computing clusters 1909 a, 1909 b,1909 c arranged as server system, in accordance with an exampleembodiment. Computing devices 1680 and/or 1900 may be included in such acluster. In some embodiments, computing devices 1680 and/or 1900 may bea single computing devices residing in a single computing center; e.g.,within autonomous vehicle 1600. In other embodiments, computing devices1680 and/or 1900 may include multiple computing devices in a singlecomputing center, or even multiple computing devices located in multiplecomputing centers located in diverse geographic locations.

In some embodiments, data and services at computing devices 1680 and/or1900 may be encoded as computer readable information stored innon-transitory, tangible computer readable media (or computer readablestorage media) and accessible by programmable devices, such as mobiledevices, laptop or desktop computers, smart phones, and/or othercomputing devices. In some embodiments, data at computing devices 1680and/or 1900 may be stored on a single disk drive or other tangiblestorage media, or may be implemented on multiple disk drives or othertangible storage media located at one or more diverse geographiclocations.

FIG. 19B depicts a server system in accordance with an exampleembodiment. In FIG. 19B, the functions of computing devices 1680 and/or1900 may be distributed among three computing clusters 1909 a, 1909 b,and 1909 c. Computing cluster 1909 a may include one or more computingdevices 1900 a, cluster storage arrays 1910 a, and cluster routers 1911a connected by a local cluster network 1912 a. Similarly, computingcluster 1909 b may include one or more computing devices 1900 b, clusterstorage arrays 1910 b, and cluster routers 1911 b connected by a localcluster network 1912 b. Likewise, computing cluster 1909 c may includeone or more computing devices 1900 c, cluster storage arrays 1910 c, andcluster routers 1911 c connected by a local cluster network 1912 c.

In some embodiments, each of computing clusters 1909 a, 1909 b, and 1909c may have an equal number of computing devices, an equal number ofcluster storage arrays, and an equal number of cluster routers. In otherembodiments, however, each computing cluster may have different numbersof computing devices, different numbers of cluster storage arrays, anddifferent numbers of cluster routers. The number of computing devices,cluster storage arrays, and cluster routers in each computing clustermay depend on the computing task or tasks assigned to each computingcluster.

In computing cluster 1909 a, for example, computing devices 1900 a maybe configured to perform various computing tasks of computing devices1680 and/or 1900. In one embodiment, the various functionalities ofcomputing devices 1680 and/or 1900 may be distributed among one or moreof computing devices 1900 a, 1900 b, and 1900 c. Computing devices 1900b and 1900 c in computing clusters 1909 b and 1909 c may be configuredsimilarly to computing devices 1900 a in computing cluster 1909 a. Onthe other hand, in some embodiments, computing devices 1900 a, 1900 b,and 1900 c may be configured to perform different functions.

In some embodiments, computing tasks and stored data associated withcomputing devices 1680 and/or 1900 may be distributed across computingdevices 1900 a, 1900 b, and 1900 c based at least in part on theprocessing capacity of computing devices 1680 and/or 1900, theprocessing capabilities of computing devices 1900 a, 1900 b, and 1900 c,the latency of the network links between the computing devices in eachcomputing cluster and between the computing clusters themselves, and/orother factors that may contribute to the cost, speed, fault-tolerance,resiliency, efficiency, and/or other design goals of the overall systemarchitecture.

The cluster storage arrays 1910 a, 1910 b, and 1910 c of the computingclusters 1909 a, 1909 b, and 1909 c may be data storage arrays thatinclude disk array controllers configured to manage read and writeaccess to groups of hard disk drives. The disk array controllers, aloneor in conjunction with their respective computing devices, may also beconfigured to manage backup or redundant copies of the data stored inthe cluster storage arrays to protect against disk drive or othercluster storage array failures and/or network failures that prevent oneor more computing devices from accessing one or more cluster storagearrays.

Similar to the manner in which the functions of computing devices 1680and/or 1900 may be distributed across computing devices 1900 a, 1900 b,and 1900 c of computing clusters 1909 a, 1909 b, and 1909 c, variousactive portions and/or backup portions of these components may bedistributed across cluster storage arrays 1910 a, 1910 b, and 1910 c.For example, some cluster storage arrays may be configured to store thedata of one or more computing device(s) 1680 and/or 1900, while othercluster storage arrays may store data of other computing device(s) 1680and/or 1900. Additionally, some cluster storage arrays may be configuredto store backup versions of data stored in other cluster storage arrays.

Cluster routers 1911 a, 1911 b, and 1911 c in computing clusters 1909 a,1909 b, and 1909 c may include networking equipment configured toprovide internal and external communications for the computing clusters.For example, cluster routers 1911 a in computing cluster 1909 a mayinclude one or more internet switching and routing devices configured toprovide (i) local area network communications between computing devices1900 a and cluster storage arrays 1901 a via local cluster network 1912a, and (ii) wide area network communications between computing cluster1909 a and computing clusters 1909 b and 1909 c via wide area networkconnection 1913 a to network 1914. Cluster routers 1911 b and 1911 c mayinclude network equipment similar to cluster routers 1911 a, and clusterrouters 1911 b and 1911 c may perform similar networking functions forcomputing clusters 1909 b and 1909 b that cluster routers 1911 a performfor computing cluster 1909 a.

In some embodiments, the configuration of cluster routers 1911 a, 1911b, and 1911 c may be based at least in part on the data communicationcapacity of the computing devices and cluster storage arrays, the datacommunications capabilities of the network equipment in the clusterrouters 1911 a, 1911 b, and 1911 c, the latency and throughput of localnetworks 1912 a, 1912 b, 1912 c, the latency, throughput, and cost ofwide area network links 1913 a, 1913 b, and 1913 c, and/or other factorsthat may contribute to the cost, speed, fault-tolerance, resiliency,efficiency and/or other design goals of the moderation systemarchitecture.

The above detailed description describes various features and functionsof the disclosed systems, devices, and methods with reference to theaccompanying figures. In the figures, similar symbols typically identifysimilar components, unless context indicates otherwise. The exampleembodiments described herein and in the figures are not meant to belimiting. Other embodiments may be utilized, and other changes may bemade, without departing from the scope of the subject matter presentedherein. It will be readily understood that the aspects of the presentdisclosure, as generally described herein, and illustrated in thefigures, may be arranged, substituted, combined, separated, and designedin a wide variety of different configurations, all of which areexplicitly contemplated herein.

With respect to any or all of the ladder diagrams, scenarios, and flowcharts in the figures and as discussed herein, each block and/orcommunication may represent a processing of information and/or atransmission of information in accordance with example embodiments.Alternative embodiments are included within the scope of these exampleembodiments. In these alternative embodiments, for example, functionsdescribed as blocks, transmissions, communications, requests, responses,and/or messages may be executed out of order from that shown ordiscussed, including substantially concurrent or in reverse order,depending on the functionality involved. Further, more or fewer blocksand/or functions may be used with any of the ladder diagrams, scenarios,and flow charts discussed herein, and these ladder diagrams, scenarios,and flow charts may be combined with one another, in part or in whole.

A block that represents a processing of information may correspond tocircuitry that may be configured to perform the specific logicalfunctions of a herein-described method or technique. Alternatively oradditionally, a block that represents a processing of information maycorrespond to a module, a segment, or a portion of program code(including related data). The program code may include one or moreinstructions executable by a processor for implementing specific logicalfunctions or actions in the method or technique. The program code and/orrelated data may be stored on any type of computer readable medium suchas a storage device including a disk or hard drive or other storagemedium.

The computer readable medium may also include non-transitory computerreadable media such as computer-readable media that stores data forshort periods of time like register memory, processor cache, and randomaccess memory (RAM). The computer readable media may also includenon-transitory computer readable media that stores program code and/ordata for longer periods of time, such as secondary or persistent longterm storage, like read only memory (ROM), optical or magnetic disks,compact-disc read only memory (CD-ROM), for example. The computerreadable media may also be any other volatile or non-volatile storagesystems. A computer readable medium may be considered a computerreadable storage medium, for example, or a tangible storage device.

Moreover, a block that represents one or more information transmissionsmay correspond to information transmissions between software and/orhardware modules in the same physical device. However, other informationtransmissions may be between software modules and/or hardware modules indifferent physical devices.

The particular arrangements shown in the figures should not be viewed aslimiting. It should be understood that other embodiments may includemore or less of each element shown in a given figure. Further, some ofthe illustrated elements may be combined or omitted. Yet further, anexample embodiment may include elements that are not illustrated in thefigures.

While various aspects and embodiments have been disclosed herein, otheraspects and embodiments will be apparent to those skilled in the art.The various aspects and embodiments disclosed herein are for purposes ofillustration and are not intended to be limiting, with the true scopebeing indicated by the following claims.

What is claimed is:
 1. A method comprising: based on sensor input,detecting, by an autonomous vehicle, a condition in which the autonomousvehicle is impeded from traveling according to a first trajectory;transmitting, by a communication unit of the autonomous vehicle and byway of a wireless network, an assistance signal to an assistance centerthat is remote from the autonomous vehicle, wherein the assistancesignal indicates that the autonomous vehicle seeks assistance travelingaccording to the first trajectory; receiving, by the communication unitof the autonomous vehicle and by way of the wireless network, a responseto the assistance signal, wherein the response includes a representationof a second trajectory; and instructing, by a control unit of theautonomous vehicle, the autonomous vehicle to travel according to thesecond trajectory.
 2. The method of claim 1, further comprising: beforereceiving the response to the assistance signal, receiving, from theassistance center, a request for sensor data; and in response toreceiving the request for sensor data, transmitting, to the assistancecenter, the requested sensor data.
 3. The method of claim 2, furthercomprising: before transmitting the requested sensor data, obtaining therequested sensor data from one or more sensors of the autonomousvehicle.
 4. The method of claim 1, wherein the second trajectory ignoresa presence of at least one object that obstructs the first trajectory.5. The method of claim 1, wherein the second trajectory is differentfrom the first trajectory and the second trajectory intersects the firsttrajectory at two or more points.
 6. The method of claim 1, wherein thesecond trajectory is different from the first trajectory and the secondtrajectory is a modified version of the first trajectory.
 7. The methodof claim 1, wherein the second trajectory and the first trajectory areidentical.
 8. The method of claim 1, wherein detecting the condition inwhich the autonomous vehicle is impeded from traveling according to thefirst trajectory comprises: identifying a cause for the autonomousvehicle to be impeded from traveling according to the first trajectory;starting a timer, wherein length of the timer is based on the cause; andafter the timer expires, determining that the cause is still impedingthe autonomous vehicle from traveling according to the first trajectory.9. The method of claim 1, further comprising: after traveling accordingto the second trajectory, determining that the autonomous vehicle cansafely return to traveling according to the first trajectory; and inresponse to determining that the autonomous vehicle can safely return totraveling according to the first trajectory, instructing the autonomousvehicle to travel according to the first trajectory.
 10. An autonomousvehicle comprising: a sensor unit; a communication unit; a propulsionunit; and a control unit configured to: based on input from the sensorunit, detect a condition in which the autonomous vehicle is impeded fromtraveling according to a first trajectory; cause the communication unitto transmit, by way of a wireless network, an assistance signal to anassistance center that is remote from the autonomous vehicle, whereinthe assistance signal indicates that the autonomous vehicle seeksassistance traveling according to the first trajectory; receive, by ofthe communication unit and by way of the wireless network, a response tothe assistance signal, wherein the response includes a representation ofa second trajectory; and instruct the propulsion unit to cause theautonomous vehicle to travel according to the second trajectory.
 11. Theautonomous vehicle of claim 10, wherein the control unit is furtherconfigured to: before receiving the response to the assistance signal,receive, by way of the communication unit and from the assistancecenter, a request for sensor data; and in response to receiving therequest for sensor data, cause the communication unit to transmit, tothe assistance center, the requested sensor data.
 12. The autonomousvehicle of claim 11, wherein the control unit is further configured to:before transmitting the requested sensor data, obtaining the requestedsensor data from the sensor unit.
 13. The autonomous vehicle of claim10, wherein the second trajectory ignores a presence of at least oneobject that obstructs the first trajectory.
 14. The autonomous vehicleof claim 10, wherein the second trajectory is different from the firsttrajectory and the second trajectory intersects the first trajectory attwo or more points.
 15. The autonomous vehicle of claim 10, wherein thesecond trajectory is different from the first trajectory and the secondtrajectory is a modified version of the first trajectory.
 16. Anon-transitory computer readable medium storing instructions thereonthat, when executed by one or more processors of a control unit, causethe control unit to perform operations comprising: based on sensorinput, detecting a condition in which an autonomous vehicle is impededfrom traveling according to a first trajectory; transmitting, by way ofa wireless network, an assistance signal to an assistance center that isremote from the autonomous vehicle, wherein the assistance signalindicates that the autonomous vehicle seeks assistance travelingaccording to the first trajectory; receiving, by way of a wirelessnetwork, a response to the assistance signal, wherein the responseincludes a representation of a second trajectory; and instructing theautonomous vehicle to travel according to the second trajectory.
 17. Thenon-transitory computer readable medium of claim 16, the operationsfurther comprising: before receiving the response to the assistancesignal, receiving, from the assistance center, a request for sensordata; and in response to receiving the request for sensor data,transmitting, to the assistance center, the requested sensor data. 18.The non-transitory computer readable medium of claim 17, the operationsfurther comprising: before transmitting the requested sensor data,obtaining the requested sensor data from one or more sensors of theautonomous vehicle.
 19. The non-transitory computer readable medium ofclaim 16, wherein the second trajectory ignores a presence of at leastone object that obstructs the first trajectory.
 20. The non-transitorycomputer readable medium of claim 16, wherein the second trajectory isdifferent from the first trajectory and the second trajectory intersectsthe first trajectory at two or more points.